Everything people ask about the PRV V6 — origins, architecture, generations, engine codes, the cars that used it — answered in a few factual sentences, sourced from this site.
The PRV V6 is a 90° petrol V6 engine born of the alliance between Peugeot, Renault and Volvo. It was built from 1974 to 1998 at Douvrin, in northern France, by La Française de Mécanique — 970,315 units in total.
Because it descends from an aborted V8: the 3,550 cc 90° V8 developed by Peugeot and Renault for the Renault “Project H” luxury saloon. After the 1973 oil crisis buried the V8, engineers removed two cylinders and kept the 90° architecture — unusual for a V6, whose norm is 60°. The Journal article →
The first (1974–1985) has non-offset crankpins and uneven firing, fed by carburettors or mechanical injection — 2,664 and 2,849 cc, 12 valves. The second (1985–1992), introduced with the Renault 25 V6 Turbo, gains a forged crankshaft with offset crankpins for smooth running, electronic injection and turbocharging. The third (c. 1989–1998) modernises the 3.0-litre: displacement raised to 2,963 cc (Z7X), a balance shaft, hydraulic tappets in place of the rockers, sodium-filled exhaust valves on the turbo versions — and 24-valve heads from 1990. R25 file →
In the Library: the workshop sheets for the A610's Z7X-744 (250 bhp) and the V6 GT Turbo's Z7U-730 (200 bhp) give pressures, ignition, torque figures and capacities. The carburettored A310 and the naturally aspirated V6 GT have their own too.
Yes, twice over: Citroën Technical Note no. 23 explains how it works (Fenix 4 injection, ACAV variable intake), and the ZPJ4 workshop sheets give the values — on the 605 SV 24 side and on the XM V6.24 side, 200 bhp on both.
With the 4097 T decoder or a Citroën 26 A station plugged into the green self-diagnosis socket: the ECU stores faults and reads them back as codes. Citroën Technical Note no. 4 lists them all — 12 sequence start, 11 sequence end, 13 air temperature, 14 water temperature, 15 fuel pump relay, 21 throttle potentiometer, 33 absolute pressure sensor, 56 coded immobiliser — then two pages of methodical tables giving, code by code, what to check, where, and to what value. One warning the note prints in capitals: cutting the ECU's power supply erases the stored list, resets the adaptive corrections and arms the immobiliser.
The three-litre 12-valve PRV V6 of the XM in its 15-04 standard form, built for export outside the stricter emission markets. Same dimensions as the ZPJ — 93 mm bore, 73 mm stroke, 2,975 cc, 9.5:1 compression — for 123 kW EEC, that is 170 bhp DIN at 5,600 rpm, and 24.5 m.kg DIN at 4,600 rpm. Citroën Technical Note no. 4 is explicit: the engine is identical to the ZPJ, only the engine number differs.
Because its emission control runs open loop. The Fenix 3B ECU is therefore specific to it, and so is the exhaust: the centre pipe carries no sensor and holds an uncoated catalyst. With no permanent mixture correction, richness is set in the workshop with a potentiometer.
With the Bendix potentiometer — grey 2-pin connector, in the electronic control box: it is the one component specific to this installation, and it stands in for the oxygen sensor. Conditions: run-in car, engine hot, clean air filter, ignition, air circuit and exhaust in good order, idle at 750 rpm. CO must fall between 1 and 1.6% on a gas analyser, then the tamper cap goes back on.
No. Idle speed is set by the ECU-controlled idle valve at about 750 rpm when hot. The note says it in capitals: do not touch the throttle stop screw. Ignition is not adjustable either — timing comes from the map programmed into the ECU.
On pins 9 and 17 of the ECU: 0.5 ± 0.1 volt with the throttle closed, 4.5 volts at full throttle. Before that, set the drive roller on the control spindle — closed throttle, it must turn freely but without play over a 3 mm movement of the sector, measured with a drill bit for instance.
EYQUEM RFC 58 LS3, flat seat. Electrode gap 1 ± 0.1 mm, tightening torque 1.5 mdaN.
No, and the note makes a point of repeating it: no re-torque at 1,500 km on this V6's cylinder heads.
There is no way round it: the ECU becomes unusable, and the Fenix 3B must be replaced to start the engine again. Replacement ECUs from the parts department come with code 0001 in memory followed by the neutral code 0000 — like new cars, delivered in transparent code 0000 but holding 0001 in memory.
The customer switches on and enters their personal code. The service receptionist then presses “C”, types 0000 and presses “C” again. When the car is handed back, the customer switches on and enters their code: the immobiliser is armed again.
Because any interruption of the ECU's supply erases the stored fault list, resets the adaptive corrections and arms the coded immobiliser. The note therefore sets an order: neutralise the immobiliser, preliminary checks, connect the break-out box, road test if needed, read the code, find the fault, repair, erase the code.
The note gives the whole tree. Ignition: 12 to 14 volts on coil terminal 2, primary at 0.5 Ω and secondary at 6,500 Ω. Fuel: about 3 bar while cranking, 12 to 14 volts on terminal 5 of the pump relay and about 9 volts at the pump. And first of all, always: the system earths and the connections of the pump, ECU, absolute pressure sensor, speed sensor, injectors and battery.
A known fault, covered by INFO'RAPID no. 6 of 29 September 1989, which applies to every XM: the valve blocks, its ball jamming under low tank pressure. The fix: remove the inner shield of the right rear wheel arch and fit the green vent valve, part no. 96 032 015. Note that this valve requires an unvented fuel cap, part no. 92 554 327.
Eight destinations, listed in the note: Spain, Portugal, Réunion, Martinique, Guadeloupe, French Guiana, Jamaica and the Gulf states. Equipment varies with the destination — exhaust without catalyst, pre-filter on the air circuit, canister, radiator, fan, water/oil heat exchanger, uprated sphere diaphragms, alternator, starter, battery. Cars for Jamaica are right-hand drive, covered by a separate technical note.
Our Library holds the complete series of Pub et Trade professional data sheets — fifteen PRV V6 variants, one sheet each, searchable page by page: Renault 25 (Z7U 205 and 182 bhp, Z7V 144, Z7W 160 and 153), Safrane V6 (Z7X-722/723), Laguna (Z7X-760), the Alpines (A310 carburettors 1978, V6 GT Z6W, V6 GT Turbo Z7U-730, A610 Z7X-744 250 bhp), Peugeot 605 (ZPJ and ZPJ4 SV 24) and Citroën XM (ZPJ and ZPJ4 V6.24). Each sheet gives sensor resistances, fuel and boost pressures, ignition, cylinder-head torque, valve clearances and capacities. Open the Library →
Yes, in the Library, since September 2026. For Volvo, the three manuals covering the B27 and B28 of the 260s (1975-1983): repairs and maintenance, reconditioning, and the CI K-Jetronic fuel system. For the DeLorean DMC-12, the Dunmurry workshop manual (engine, fuel and emissions, ignition) and the 1981 dealer training manual, which explains the engine before repairing it. For the Eagle Premier and Dodge Monaco, the 1990 service manual (engines, MPI injection, cooling, ignition, manifolds, emissions) and the Chrysler overhaul training book. Only the parts dealing with the PRV engine were taken from each: starter, alternator and body wiring were left out. Open the Library →
A 2,849 cc rear-mounted engine — 91 mm bore, 73 mm stroke, 8.8 compression ratio — giving 130 bhp SAE net at 5,500 rpm and 220 Nm at 2,750, with Bosch K-Jetronic injection and a Lambda system for the American market. Its figures come from the DeLorean training manual, in the Library. It is an uneven-fire PRV, that is to say the original three-crankpin crankshaft: the split-crankpin, even-fire version came later. Same capacity as the Volvo B28. See the specifications →
In our Library, the Pub et Trade workshop data sheet (ref. REN-82B, 1991) gives every setting for the Z7U-A700: Bendix injection and its sensor resistances by temperature, the SEM boost-control solenoid, the Garrett T3, cylinder-head torque (6 m.daN then 127°), valve clearances cold (0.10 intake / 0.25 exhaust) with the rocker sequence table, capacities and electrics. The PDF is searchable page by page. Open the Library →
A Peugeot 604 Limousine bodied by Heuliez (1982), stretched by 62 cm and powered by the PRV V6 (ZMJ, 2,664 cc): Philippe Bouvard had it fitted out as a genuine rolling office — glazed driver partition, PTT-issued 150 MHz radiotelephone, typewriter, on-board secretaries — to write his columns on the road. He donated it in 1998 to L'Aventure Peugeot; it is on display at the Sochaux museum with its period fittings intact. The full story →
In competition, the PRV ran twin-turbocharged from the 1980s: the WM P88 at Le Mans drew around 910 bhp from it and set the 407 km/h record in 1988. On the road, the first attempt was the DeLorean Twin Turbo, entrusted by John DeLorean to Legend Industries in the early 1980s: DMC's bankruptcy in 1982 killed it after four cars had been converted, two of them twin-turbo. It therefore took until 1994 and the Renault Safrane Biturbo for a twin-turbo PRV V6 to actually be sold as a production car — the 408 bhp Venturi 400 GT followed a few months later, in June.
Five displacements: 2,458 cc (turbo), 2,664 cc, 2,849 cc, 2,963 cc and 2,975 cc — with outputs from 125 bhp (Volvo 264) up to 408 bhp (Venturi 400 GT) on road cars.
At Renault, Peugeot and Citroën, PRV V6 units carry Douvrin “Z-codes”: Z6V and Z7V (2.7 L), Z7U (2.5 L turbo), Z7W (2.8 L) and Z7X (3.0 L). Volvo used its own B-codes: B27, B28 and B280. Each family has its own file: Z7U, Z7X, ZPJ4, Peugeot codes, Renault codes and Volvo B-codes.
Only the phase 1 Laguna 3.0 V6 12-valve (Z7X, 167 bhp) is a PRV. From 1997 — and only in April 1999 on the Safrane — a 60° “PR” V6 — L7X at Renault, ES9 at Peugeot — replaced the PRV on the Laguna, Espace, 605 and XM. That engine is not a PRV. Laguna file → · Safrane file → · Espace file →
ACAV stands for “Admission à Caractéristiques Acoustiques Variables”: a variable-geometry intake on the PSA ZPJ4 3.0-litre 24-valve (200 bhp) that changes runner length with engine speed, giving nearly 80% of the torque from low revs on a naturally-aspirated V6. ZPJ4 file →
PRV stands for Peugeot-Renault-Volvo: the three carmakers of the alliance behind this V6, Volvo joining Peugeot and Renault in 1971 as an equal partner. The full story is in the History section; the engine itself — architecture, generations, codes — has its own page: The PRV V6 engine →
No. Every PRV V6 carries a code from one of the three partners: the Douvrin Z-codes at Renault (Z6V, Z7V, Z7U, Z7W, Z7X) and at Peugeot — shared with Citroën within PSA (ZM, ZMJ, ZNJ, ZN3J, ZPJ, ZPJ4) — and the B-codes at Volvo (B27, B28, B280). The other marques bought the engine as it was: Alpine under Renault codes (Z7U in the GTA Turbo, Z7X 744 in the A610), DeLorean under the Peugeot ZMJ (ZMJ-159 variant), Eagle and Dodge under the Z7X (711 and 715), Lancia under the ZN3J, Venturi under Z7U, Z7W and ZPJ4 units prepared by EIA. No carmaker ever struck a PRV code in its own name. Every known code →
At Douvrin, near Lens in northern France, by La Française de Mécanique (founded in 1969). All 970,315 units were built there.
In October 1974, in a Volvo 264 — the Douvrin lines had been running since January 1974. Volvo 260 file →
On 15 June 1998, at Douvrin, after a total of 970,315 units across 24 years of production.
A Renault luxury saloon abandoned in July 1967. Its 3,550 cc 90° V8, developed jointly by Peugeot and Renault, passed its architecture on to the PRV when the 1973 oil crisis steered the project towards a V6.
Because its crankpins are not offset: on a 90° V6 this gives uneven firing. The second generation (1985) adopted offset crankpins and finally ran smoothly.
The 2,458 cc Z7U, launched in 1985 by the Renault 25 V6 Turbo — which also opened the second generation. Z7U file →
Yes, from 1990 at PSA: the ZPJ4 of the Peugeot 605 SV24 and Citroën XM V6 24S, 200 bhp naturally aspirated thanks to the ACAV variable intake. ZPJ4 file →
Around 5,200 rpm: below that, the long runners exploit resonance to swell torque (nearly 80% from low revs); above it, the geometry opens to free top-end power.
Around 910 bhp for the twin-turbo ZNS5 of the WM P88 in racing (1988). On the road: 408 bhp for the Venturi 400 GT.
Yes: despite the divorce pronounced in 1992, Volvo saloons kept fitting the PRV until 1997.
The 60° “PR” V6 that succeeded the PRV from 1997 (L7X at Renault, ES9 at Peugeot) on the Safrane, Laguna, Espace, 605 and XM. It is not a PRV.
Carburettors (including SU-HIF6), K-Jetronic mechanical injection, then Renix, LH-Jetronic, Bendix and Fenix electronic injection depending on the variant.
The racing PRV of the WM P88: 2,974 cc, 24 valves, twin-turbo — around 910 bhp, the most powerful PRV ever built. Record file →
The turbocharged 2,458 cc PRV (180 to 210 bhp): the first turbo PRV, fitted to the Renault 25 V6 Turbo, the Alpine GTA and the Venturi 200. Z7U file →
The 2,963 cc in Renault nomenclature: from 150 bhp (Eagle, Dodge) to 268 bhp (Safrane Biturbo), including the Alpine A610's 250 bhp turbo. Z7X file →
PSA's 24-valve with the ACAV intake: 200 bhp naturally aspirated, and up to 408 bhp twin-turbocharged by EIA in the Venturi 400 GT. ZPJ4 file →
Volvo's codes for the PRV V6, from 125 bhp (carburetted B27A) to 156 bhp (LH-Jetronic B280), fitted to the 264, 265, 262C, 760 and 780. B27 file → · B28 file → · B280 file →
In 1968. The SAE paper says so in its opening lines: work began that year on an engine “with a comparatively large cubic displacement to be fitted in prestige European cars”, and that consideration alone already pointed to a six-cylinder. SAE paper 760110, page 2. Library →
Three authors, one per company: François Gastinne (Société Anonyme des Automobiles Peugeot), M. Lalière (Régie Nationale des Usines Renault) and Stephen Wallman (AB Volvo). Presented at the SAE Automotive Engineering Congress and Exposition in Detroit, 23-27 February 1976. SAE paper 760110, page 1. Library →
Because its natural torsional frequency is very high compared with other six-cylinders — “thanks to its three crank-pin crankshaft instead of 6 for others”, the authors write. Figure 1 of the paper plots torsional amplitudes across the whole speed range. The engine also retains a good ability to run properly at low speed and full load. SAE paper 760110, page 2. Library →
About 250 mm for the same displacement. The saving pays twice over: the car can be shortened by as much, and an aluminium cylinder block becomes possible. The authors are candid about the trade-off: a V layout is more complicated to build and would make the engine heavier for the same material — compactness is what turns the balance around. SAE paper 760110, page 2. Library →
Because you go from the 13,000 daN/mm² modulus of elasticity of cast iron to the 7,500 daN/mm² of aluminium. Such a modulus is consistent only with compact structures, otherwise structural vibration follows. The compactness of the 90° V6 was therefore not a nicety: it was the condition for the light-alloy block. SAE paper 760110, page 2. Library →
A 2nd-order sinusoidal torque, its axis perpendicular to the crankshaft and lying in the bisecting plane of the two banks. Correcting it would take complicated, costly devices at the expense of mechanical efficiency — the authors knowingly decline. The “free movement” of the 90° V6, measured at the outer main bearings, is nevertheless six times smaller than that of a four-cylinder of the same unit displacement: hence great freedom in choosing engine mounts, and noise transmitted to the body that is “practically imperceptible”. SAE paper 760110, pages 2 and 3. Library →
Because the three-crankpin crankshaft forces unequal angular intervals: 90° then 150°, three times per cycle. It is the direct price of the three-crankpin choice — the very one that gives the engine its rev range. SAE paper 760110, page 3. Library →
17.5 mm. It follows from two linked constraints: the minimum cylinder liner bore diameter, which sets connecting-rod dimensions and hence crank-pin diameter; and the specific pressure allowed on the aluminium-tin bearing material, which imposes a bearing width and hence the width of the big end. Reaching the minimum value was essential: it affects both overall length and the efficiency of the transverse structural ribs. SAE paper 760110, page 4. Library →
Figure 3 of the paper spells them out. Crank-pin: distance between arms 40 mm, bearing width 17.5 mm, ⌀ 52.3 mm, bearing surface 9.16 cm², calculated specific pressure 425 daN/cm². Main bearing: 29.6 mm, width 23.4 mm, ⌀ 70 mm, bearing surface 16.35 cm², specific pressure 141 daN/cm². Compare with the workshop manual, which gives “crankpins ⌀ 60 mm or 52.290 depending on type”: the manual's 52.290 is the 1976 crank-pin, still in service alongside the 60 mm that came later. SAE paper 760110, page 4 (figure 3) and page 14; Z engines manual, folio 10-35. Library →
14.3 kg bare, without caps or liners; 27 kg with cast-iron caps and liners. Overall length 392.5 mm, distance from crankshaft axis to the head gasket face 221 mm, and to the lower gasket face 60 mm. Block in die-cast AS9U3, with separate wet cast-iron liners — chosen to allow a “low silicon” alloy (simpler die casting, less tool wear) and conventional pistons. SAE paper 760110, page 5. Library →
The most heavily loaded is bearing No. 3, at full load and 6100 rpm: a separating force of 2180 daN and a sliding force of 750 daN. (Bearing No. 1 is the outermost one on the clutch side.) The size of those forces, together with the concern to reduce crankshaft-to-bearing clearance — experimentally recognised as essential to control full-load noise — led to the cast-iron caps enclosed between block and lower housing. SAE paper 760110, pages 5 and 6. Library →
146.15 mm centre-to-centre, giving a rod/crank ratio of 4.01 with the 73 mm stroke. That is no accident: the smaller the interfering 2nd-order torque, the longer the rod. Rods are forged, of a single type, just as there is one crankshaft type and one piston weight — interchangeability is complete, with no matching. SAE paper 760110, pages 6 and 14. Library →
Like a V8's: by attaching to each crank-pin, by hand or on a suitable cradled holder, centred additional masses worth twice the rotating mass of a connecting rod (2 × 0.557 kg) plus once the reciprocating mass for one cylinder (0.796 kg) — complete piston and rod small end. First-order balance is handled by six counterweights, whose position, mass and geometry were determined to balance the rotating torque while keeping bearing loads to a minimum. SAE paper 760110, pages 5 and 6. Library →
To take advantage of the offset between the banks and save 10 mm in length: it is, the authors write, the only solution that allowed it. Each chain is tensioned on its slack side by a long steel blade padded with Nylatron — a 66-nylon with 30% molybdenum disulfide —, hinged near the crankshaft and pressed at the other end by an oil-pressure pushrod with a non-return device. SAE paper 760110, page 7. Library →
156 kg — European carburettor version, with air filter, flywheel, water pump, alternator, fluid-drive cooling fan, starter motor and oil, but without engine mounts or brackets. Dimensions: length 466.5 mm (from the first belt working plane to the clutch disc friction face), height 623 mm (from oil pan to the carburettors' upper air intakes), width 632 mm (measured at exhaust manifold level). SAE paper 760110, page 14 (Appendix I). Library →
A double-barrel with simultaneous opening, its throttle plate axes parallel to the crankshaft, sitting in the middle of the V at a well-determined point along the engine — because only manifold water pre-heating was used. Developed with the Solex Carburetor Company. Two options were open: almost completely separating the ducts between banks, with a 20 mm connection hole to balance at idle and very low loads — specific torque about 8 m.daN/litre; or connecting the six ducts under the carburettor — slightly lower specific torque (7.75 m.daN/litre) but higher specific power. The second went into production, with a small additional nozzle upstream to improve mixture preparation at low load. SAE paper 760110, page 9. Library →
The brochure's box gives them in one go: 6 cylinders in a 90° V, 2975 cm³, bore × stroke 93 × 73 mm, compression ratio 7.6, maximum power 184 kW EEC — 250 hp DIN at 5750 rpm, maximum torque 350 Nm EEC — 35.7 m-kg DIN at 2900 rpm, Fenix 3B injection-ignition (Pressure-Speed system), one camshaft per head, sodium-cooled exhaust valves, aluminium rockers with bonded pads, a Garrett T3 turbo — the brochure spells it “Garett” then “Garret”, two typos for the same turbocharger — with a boost pressure of 766 mbar. PRV Z7X-744 brochure, page 2. Library →
177 kg bare. The brochure explains why the figure mattered: in the Alpine A610 the engine sits in rear overhang — its centre of gravity lies behind the rear axle. Hence aluminium for the crankcase, the heads and various covers. PRV Z7X-744 brochure, page 2. Library →
From 330 to 350 Nm EEC (34 m-kg DIN) over a 1800 to 5000 rpm range — that is the brochure's own wording. Beware of the figures in circulation: the press articles reproduced at the end of the document give different ranges (2000-5000, 2000-5200 rpm), and one even puts peak torque at 2000 rpm instead of 2900. The manufacturer's document is the authority. PRV Z7X-744 brochure, page 2; compare with pages 5 and 6. Library →
A steel crankshaft with split (offset) crankpins — the solution that makes a 90° V6 run evenly, by offsetting the two journals of each shared crankpin to compensate for the V angle. The crankshaft oil circuit was reworked for the occasion, the lubrication groove of the main bearing shells widened, and the big-end shells widened too and made of cast copper-lead. PRV Z7X-744 brochure, pages 2 and 3. Library →
By two simultaneous actions, not by ignition timing alone: a slight retard of the ignition advance and a reduction of boost pressure, until normal running returns. Boost itself is managed by the ECU through a solenoid valve placed between the manifold and the pressure regulator, creating a variable air leak — modulated by engine speed, load, throttle opening and coolant temperature. That control also serves comfort: it makes torque more progressive at part load and softens the “turbo effect”. PRV Z7X-744 brochure, page 3. Library →
Yes, the air conditioning. It anticipates fast idle when the compressor is about to be engaged, to smooth out speed variations; and it inhibits the air conditioning in the seconds following start-up, or when coolant temperature gets too high. PRV Z7X-744 brochure, page 3. Library →
On the cylinder head — the brochure is explicit, with photographs (nos. 20 to 23). They neutralise the engine's seismic displacements and improve the noise level. A diagram on page 4 shows the intended effect on powertrain resonance. So they are not to be looked for in the crankcase, contrary to what is sometimes written. PRV Z7X-744 brochure, page 4. Library →
The Public Relations department of the Société des Moteurs PRV, at Douvrin, 62138 Haisnes — the very plant where the engine was built. The scanned copy carries a handwritten dedication dated 10/04/91, addressed to Stephen (Wallman, one of the three signatories of the 1976 SAE paper) to share the press reception with him. PRV Z7X-744 brochure, pages 1 and 7. Library →
Because its architecture was reworked for the sole purpose of equalising the firing intervals between cylinders, with an all-new forged steel crankshaft with split (offset) crankpins. The proof is in the valve timing table: the Z6W-A700 keeps two different laws depending on the bank — right 12° / 45° / 50° / 6°, left 10° / 47° / 52° / 5° — while the Z7U-730 shows 8° / 40° / 40° / 8° on both sides. Offsetting the crankpins erased the asymmetry the 90° V6 had carried since 1976. élan no. 77, February 1985, pages 3 and 4. Library →
Far more than a turbo. élan 77's list: a forged steel crankshaft with split crankpins whose stroke drops from 73 to 63 mm; new connecting rods, made necessary by the larger crankpin diameter; new pistons with floating gudgeon pins; heads with a stiffened deck and bronze valve guides; valves with metallurgy suited to forced induction; a reinforced head gasket; forced induction by a Garrett T3 sitting at the rear of the V, with an air-to-air intercooler and a compressor bypass valve; and Rénix electronic injection with coupled ignition, idle regulation, overrun cut-off, knock detection and rev-limiter cut. élan no. 77, February 1985, page 4. Library →
élan 77's table sets them side by side. Z6W-A700: 91 × 73 mm, 2849 cm³, compression ratio 9.5:1, 116 kW ISO — 160 hp DIN at 5750 rpm, torque 221 Nm ISO — 23 m-kg DIN at 3500 rpm, two Solex carburettors (a single-barrel 34 TBIA and a twin-barrel 35 CEEI), breakerless transistorised ignition. Z7U-730: 91 × 63 mm, 2458 cm³, compression ratio 8.6:1, 147 kW ISO — 200 hp DIN at 5750 rpm, torque 285 Nm ISO — 29.6 m-kg DIN at 2500 rpm, electronic injection, fully electronic ignition with knock sensor. Common to both: 97/99 super, all light alloy, removable wet liners, hemispherical chamber, 4 main bearings, one overhead camshaft per bank driven by its own simplex chain, valves in a V operated by rockers, firing order 1-6-3-5-2-4, 88 °C thermostat, two 290 mm 120 W electric fans. élan no. 77, February 1985, page 4. Library →
élan 77 gives the exact definition in a footnote: the maximum spread, as a percentage, of instantaneous rotational speeds through the cycle, relative to mean speed. And the figure: as engine speed rises from 2000 to 5500 rpm, the V6's cyclic regularity becomes 1.5 to 3 times better than a four-cylinder of the same unit displacement. “That is what the muted feel of a V6 expresses”, the article concludes. élan no. 77, February 1985, page 3. Library →
More than 80,000. élan 77 uses it as an argument: the PRV V6 already had versions able to meet the strictest emission standards, and those 80,000 American engines were the proof — enough, the magazine writes, to vindicate Renault Alpine's choice. élan no. 77, February 1985, page 4. Library →
The staff magazine of la Française de Mécanique — the Douvrin plant where the PRV V6 was built. Issue 77, February 1985, opens on the two PRV engines of the new Renault Alpine V6. Publication director and editor-in-chief Georges Crapet, Public Relations department, B.P. 8, 62138 Haisnes; print run 7,500 copies, printed in Douai, legal deposit Q1 1985. Its cover is a photographic study made from the exhaust manifold gaskets of the PRV V6. élan no. 77, February 1985, page 2. Library →
The association wrote a three-page guide for its group order of reinforced SAMCO hoses, on the longitudinally mounted V6. The essential point: the hoses supplied are LONGER than the originals, because they cover several installations — you cut them to length yourself. Lay the original hose over the new one, mark its length, cut on the marks, then fit. You need a sharp craft knife, the 45 mm and 19 mm silicone tubes, two 45° elbows and the clamps. The guide is free to read in the Library.
About 152 kg with its ancillaries, according to the Renault 30 manual — the first car to receive it. The manual also gives the complete unit: 225 kg for the « engine + manual gearbox » assembly, 240 kg for « engine + automatic gearbox ». These figures are for the 2,664 cc of 1975; they give the order of magnitude of what you lift when you take a PRV out. Renault 30 M.R.167, folio B-3.
Upwards — the manual boxes it: removed on its own, the engine is lifted out from above, and its lifting eyes make the job easier. Removal: disconnect the battery; remove the bonnet and the undertray; drain the coolant at the radiator and at the block — key Mot. 593 for plugs A and B — and the engine oil if needed; on automatics, the two oil lines at the radiator. Remove the air filter, the radiator and fan cowl, and the diagnostic socket; disconnect all hoses, wiring, cables and exhaust clamps; free the power steering reservoir and take off the alternator's V-belt; remove the cover plates at the starter ring and at the clutch or torque converter. Loosen the engine mounting bolts; on automatics, remove the converter bolts on the drive plate. Remove the starter. Support the gearbox on a wedge, fit two slings Mot. 477 to the four lifting eyes, lift the engine-gearbox unit, remove the two rubber engine mounts, lower the unit until the gearbox rests on the wedge, remove the upper and lower engine-to-gearbox bolts — and lift the engine out. Refitting: reverse order; mind the diagnostic socket (Electrical chapter); on manual gearboxes, lightly grease the clutch shaft splines with Molykote BR 2; adjust the throttle cable (and, on automatics, the cable of the gear-change governor); oil if needed, check the automatic's level, fill with coolant and bleed. A detail from the overhaul pages that goes with it: the clutch shaft spigot bearing is not fitted to spare crankshafts or exchange engines, and must be pressed in on cars with a manual gearbox — and a removed one, extracted with Mot. 11, is not reused. Renault 30 M.R.167, folios B-14 and B-16 to B-24.
Both, depending on the job. Engine alone, upwards, with lifting tackle Mot. 597 on its lifting eyes: drain the coolant at A and B, disconnect wiring, coolant, fuel and brake vacuum hoses and the throttle cable; remove the air filter, the exhaust intermediate pipes, the rear silencer and its brackets, and the clutch slave cylinder; on air-conditioned cars, the belt and the compressor, laid in the left rear wing space without opening its hoses; remove the starter bolts and the clutch cover plate carrying the TDC sensor; remove the lower mount nuts, lift slightly, support the gearbox, remove the mounts, the reverse-light switch wires and the engine-to-gearbox bolts, and lift slowly. On refitting: Molykote BR 2 on the clutch shaft splines, the starter cover plate not forgotten, TDC sensor about 0.5 to 1 mm from the flywheel, and the exhaust centred and tightened in order — manifold flange, rear silencer clamp, silencer upper mountings. Engine and gearbox with the subframe, downwards: on AC cars, drain the gearbox, drive out the left driveshaft's roll pin (B.Vi. 606), tip the stub axle carrier to free the shaft, and park the compressor in the left wing with its hoses. Then gear controls, reverse lock-out cable, earth strap, air filter, slave cylinder, hoses, cables, starter lead and expansion tank. Two boxed rules: the drive unit MUST be supported with tool MS 1026, so it stays stable on the rear axle joints and cannot tip when the six subframe bolts come out — and never remove those bolts with the wheels hanging. A tube under the lift, chained to the subframe, stops it tipping; axle stands must lift the car at least 85 cm. Lower the lift until the tube rests on the stands (a home-made tool in the chassis U-section), then slowly until the unit comes free; hang it by the engine's rear lifting eyes with the chain of Mot. 878, unhook the chain holding the gearbox and lower the whole drive unit. Refitting the same way from below, gearbox chained to the tube; raise to 2 cm from the subframe mountings, lower shock mountings aligned in the upper wishbones; Mot. 597 on (2 eyes rear, 4 front), set the subframe parallel to the body and take up its tension so the centring sleeves align; subframe bolts Ø 12: 8 daN.m, Ø 14: 10 daN.m. Brake calipers with Loctite Frenbloc at 12.5 daN.m; on its wheels, lower shock mountings 7 daN.m, upper left wishbone bolt 10 daN.m, and the driveshaft roll pins sealed with CAF 4/60 Thixo. Separating engine from gearbox on the subframe: loosen the mounts, remove the gearbox vibration limiter and lower mount nut, the speed sender (keep its spacer) and the exhaust pipes, drive out the roll pins, lift slightly on Mot. 878, free the left driveshaft by pushing the gearbox the other way, then the right — minding the oil temperature sensor on the side of the sump. Alpine M.R.273, folios B-4 to B-11.
The manual gathers them in one table, in m.kg. Crankshaft pulley nut 17, with Loctite. Flywheel bolts 4.5, with Loctite. Lower crankcase bolts on the block 1.5 to 2. Oil pump drive sprocket bolts 0.5 to 0.75, with Loctite. Timing chain tensioner spring bolt 1 to 1.5, with Loctite. Timing cover bolts 1 to 1.5, the lower ones with Loctite. Camshaft sprocket bolt 7 to 8 — a 10 mm hex-socket bolt. Intake manifold bolts 1 to 1.5. Conical-seat, long-reach spark plugs, no washer, 1.7 to 2, with key 79 10 245 598. Camshaft pulley bolts 9.5 to 10.5. The cutaway drawing repeats the main ones: 7 to 8 at the camshaft sprocket, 9.5 to 10.5 at the camshaft pulley, 4.5 at the flywheel, 17 at the crankshaft pulley, 1 to 1.5 at the timing cover. The procedure pages give single values inside these ranges — 0.6 for the oil pump sprocket, 7.5 for the camshaft sprocket. Mechanical fuel pump: static pressure with the pump not delivering, measured with the fuel level at the height of the pump diaphragm — 0.17 bar minimum, 0.27 bar maximum. Carburettors: one single-barrel Solex 34 TBIA and one twin-barrel Solex 35 CEEI. And a parts note: the engines may have either of two piston types; the parts department supplies only type 2, which is interchangeable with type 1. Renault 30 M.R.167, folios B-5, B-10 and B-14.
Every answer below comes from a manual in the Library, with its printed folio. Values are quoted, never estimated — and where the manual forbids something, we say so.
Because they contain sodium, which ignites on contact with water. The manual requires neutralising it before scrapping: saw the stems at the tulip, in a dry room, away from water and never on a wet grinder, wearing eye protection; drop the cut valves straight into a container of water placed outdoors — about 10 litres for four valves —, away from any ignition source and with no smoking. Sodium forms caustic soda and releases hydrogen: destruction is complete when the bubbling stops. Z engines manual, folio 10-28. Library →
Yes: about 30 seconds of idling. Otherwise the turbocharger, spun up by one last throttle opening, keeps turning on its own inertia without oil — engine stopped — and the turbine shaft may seize. After any work that disconnected the oil lines, the turbo oil circuit must also be primed before starting. Z engines manual, folio 10-47.
The flywheel bolts, every gasket and seal, and the connecting-rod nuts. Z engines manual, folio 10-47.
Cold: 0.10 mm intake, 0.25 mm exhaust. That is the rocker adjustment, on every type except the Z7X 721, 722, 723, 753, 760 and 765, which have hydraulic tappets and are not adjustable. ⚠️ Do not confuse it with the 0.35 mm “theoretical clearance” given on the valve-timing diagram page: that one is only for checking the timing and, as the manual itself says, “has no relation to the running clearance values”. Z engines manual, folios 10-20 and 10-34.
Threads and bolt-head undersides oiled with engine oil, bolt holes emptied with a syringe. In the prescribed order: 6 daN.m. Wait 3 minutes, slacken one bolt at a time, then 2 daN.m and an angular tightening — 127° on Z7U (except 734) and Z7W 702, 106° on Z7U 734. Then set the valve clearances, run the engine until the fans cut in, let it cool for at least 6 hours, and finish with a further angular tightening without slackening first: 25° in the first case, 45° in the second. After that, no re-tightening at all. Z engines manual, folios 10-23 and 10-24.
No. Distortion of the gasket face must not exceed 0.05 mm, and the manual says it plainly: “No skimming is permitted.” Out of tolerance, the head is replaced. Z engines manual, folio 10-20.
Because the two banks are not symmetrical: the bank A gasket — cylinders 1, 2 and 3 — has a larger relief than the bank B one — cylinders 4, 5 and 6. Swapping them is a classic reassembly mistake. Z engines manual, folio 10-20.
1.46 mm on Z7V and Z7X; 1.70 mm on Z7U, Z6W and Z7W. Z engines manual, folio 10-21.
Z7X: 110.83 mm for 49.85 cm³. Z7U, Z7V and Z6W: 111.07 ± 0.15 mm. Z7W 702 and Z7W other than 702: 110.83 mm. Chamber volumes by type: 53.3 · 52.2 · 53.3 · 51.59 cm³. Z engines manual, folio 10-20.
8 mm stems on every type. Seat angles: 120° intake, 90° exhaust. Head diameters by engine: 43.8 to 46.5 mm intake, 37 to 39.8 mm exhaust. Z engines manual, folio 10-27.
Free length 47.2 mm (Z7V) or 47.1 mm; coil bind at 30 mm (Z7V) or 28.3 mm; wire diameter 4.2 or 4.1 mm; inner diameter 21.4 mm. Z engines manual, folio 10-27.
No. The bank A shaft carries the fuel-pump drive eccentric, the bank B one the distributor drive gear — unmachined on offset-crankpin engines. The timing profiles, however, are identical on both sides. Four bearings, end float 0.07 to 0.14 mm. Z engines manual, folio 10-30.
No. The Renault 30 M.R.167 gives two separate columns, for a theoretical clearance of 0.7 mm: left bank (A) — inlet opens 9° BTDC and closes 45° ABDC, exhaust opens 45° BBDC and closes 9° ATDC; right bank (B) — 7° and 43° at all four points. Two degrees separate the banks. Renault 30 M.R.167, folio B-8.
30° on the inlet, 45° on the exhaust — the two are not cut at the same angle. Seat widths follow: 1.7 mm inlet, 2 mm exhaust. Stem diameter is 8 mm for both, and head diameters are 44 mm inlet against 37 mm exhaust. The camshafts run in four bearings, with 0.07 to 0.14 mm end float. Renault 30 M.R.167, folio B-7.
Not the offset-crankpin one: regrinding is not permitted. On a non-offset crankshaft it is possible, but the rolled fillet must remain intact over 140° in the areas the manual indicates. Z engines manual, folio 10-35.
Four bearings, aluminium-tin shells, end float 0.07 to 0.27 mm, thrust washers in 2.30 · 2.40 · 2.45 · 2.50 mm. Crankpins ⌀ 60 mm (or 52.290 depending on type), main journals ⌀ 70.062 mm. Z engines manual, folio 10-35.
There are three families, colour-coded, and the thickness is chosen to obtain the prescribed liner protrusion. Paper: blue 0.087 · white 0.102 · red 0.122 · yellow 0.147 mm. Varnished, 1st series: red 0.116 · clear 0.136 · blue 0.166 mm. Varnished, 2nd series: yellow 0.216 · red 0.246 · green 0.276 mm. Liner protrusion: 0.13 to 0.20 mm, or 0.16 to 0.23 mm depending on the family. Z engines manual, folio 10-38.
Four, never five — the consequence of a V6's three crankpins, where an inline six lines up five. Three factory manuals say so in the same words, twenty years apart: the Renault 30 M.R.167 of March 1975 (folio B-9), the Alpine A310 2700 VA repair guide (folio B-10) and the Renault « Z engines » workshop manual, which adds « all types » (folio 10-35). M.R.167 folio B-9 · A310 guide folio B-10 · Z engines manual folio 10-35.
Nip up to 3 m.daN, then a 75° angular tightening — angle tightening as early as 1975, ahead of its time. The shells are aluminium-tin, crankshaft end float runs from 0.07 to 0.27 mm, and four thrust washer thicknesses take it up: 2.30 · 2.40 · 2.45 · 2.50 mm. Connecting rod cap bolts go to 4.5 m.daN, for a side clearance of 0.20 to 0.38 mm. M.R.167 folio B-9 · A310 guide folio B-10 · Z engines manual folio 10-35.
It depends on the crankshaft. On non-offset crankpins — Z6W, Z7V, Z7W 702 — yes: rolled crankpins 52.267 to 52.286 mm nominal, 51.967 to 51.986 reground; main journals 70.043 to 70.062, reground 69.743 to 69.762. On OFFSET-pin crankshafts, those of the Z7U, Z7X and the Z7W other than 702, the manual does not allow it. And when regrinding a non-offset crank, the rolled finish must remain intact over 140° in the areas the manual marks. Z engines manual folio 10-35 · M.R.167 folio B-9.
Minimums at 80 °C. Z6W, Z7U, Z7V: 2.2 bar at 900 rpm and 4.4 bar at 4,000. Z7W: 1 bar at idle and 4 bar at 5,500. Z7X: 2.2 bar at idle and 4.4 bar at 4,000. Checked with tool MOT. 836-05. Z engines manual, folio 10-39.
No: there are two versions, and swapping one for the other risks poor internal engine lubrication. Z engines manual, folio 10-39.
The manual does not tabulate them: it prints them on engine cross-sections, at the end of leader lines, in daN.m or degrees. Six plates, two per family: Z7V-Z6W (folios 10-10 and 10-11), Z7U-Z7W (10-12 and 10-13), Z7X (10-14 and 10-15). Each pair gives a longitudinal and a transverse section. Z engines manual, folios 10-10 to 10-15.
Pre-tighten to 3 daN.m, then an angular tightening of 75°. The same on all three families; the Z7X plate is the one that names it explicitly. Z engines manual, folio 10-15.
4.5 daN.m — and 6.5 to 7 daN.m with automatic transmission. These bolts are among the parts that must always be replaced once removed. Z engines manual, folios 10-10 and 10-47.
There isn’t one. The torque plates refer to the dedicated method: tighten, wait, slacken one bolt at a time, angular re-tighten, then a further stage after cooling. See the head-tightening question above. Z engines manual, folio 10-11.
In three stages, and the second one is a surprise. Gasket new and DRY — no sealant. Stage one: tighten the bolts to 6 daN.m in the prescribed order, to crush the O-rings. Stage two: SLACKEN every bolt. Stage three: 4 daN.m, then an angular tightening of 180° on every bolt. Each head carries eight bolts, tightened from the centre outwards, alternating between the two rows, and the same order holds for both heads. Re-torquing is done cold, at the earliest six hours after stopping a warm engine: a further 50° on each bolt, in order, with no prior slackening. Before that, the engine is run 15 minutes at 2,000 rpm to bring it up to temperature. Other torques in this chapter: intake manifold 2 daN.m, camshaft sprocket 8 daN.m, small pinion of the balancing system 2.5 daN.m, Bischoff hose clips 1.5 daN.m. ⚠️ Two of these torques are not the ones the same manual gives further on: Bischoff clamps 2.5 daN.m when refitting the turbo (folio 12-16), intake manifold on the head 1.25 ± 0.25 daN.m (folio 12-17); the extract does not say which prevails. Alpine M.R.297, folios 11-1, 11-6, 11-7, 12-16 and 12-17.
Word for word. Two manuals, two cars, two countries of publication, and the same six steps: pre-tighten to 6 daN.m in the prescribed order to crush the seals, unscrew every bolt, pre-tighten to 4 daN.m, then 180° of angular tightening; run the engine 15 minutes at 2,000 rpm; re-tighten cold, at the earliest six hours after stopping, a further 50° per bolt in order and without slackening first. The procedure belongs to the engine, not to the car — which is worth knowing when the manual for your own model is missing. The Safrane version adds the practical details the Alpine's leaves out: gasket new and dry; Autojoint AJ66 (part 77 01 422 751) around the joint between timing cover and cylinder head; a Ø 3 mm rod (a spring pin punch) pushed into each centring dowel hole so the dowel is not driven down as the head goes on; Loctite FRENETANCH on the two balancing shaft mounting bolts; tool Mot. 1209 removed only to fit the balance chain tensioner. And the warning that costs an engine strip if ignored: the key can come out of the balancing shaft, so put a cloth in the timing cover. Last detail: the dummy bearing is used only when the crankshaft has to be turned — replacing a liner-piston assembly, for instance — precisely so as not to disturb the timing. Safrane M.R.302, chapter 11 · Alpine M.R.297, folios 11-6 and 11-7.
By a different method, and one that asks for a re-torque at 500 to 1,000 km. The Renault 30's M.R.167 sets it out in two parts. At head fitting: all bolts in the prescribed order first to 2 m.kg, then to 6 m.kg, to seat the head gaskets; then the “re-torque” below. Re-torque — engine cold, minimum cooling time 6 hours: slacken bolt no. 1 alone and bring it back to 2 m.kg with the Mot. 50 torque wrench, then do the same with each of the others one at a time, in the order shown; then the final tightening with the Mot. 591 angle gauge set between wrench and socket, pointer on zero, each bolt turned until the pointer stands over 115°, in order. The manual calls for this re-torque at 500 to 1,000 km — at the free service check, after any head removal, and after an engine exchange. And one prior check without which no torque figure means anything: the head bolts must run freely in their threads — if not, screw them in and out several times before assembly. Set that beside the Z7X of the A610 and the Safrane: 6 daN.m, then every bolt slackened at once, 4 daN.m and 180°, and a cold re-torque that adds 50° without any slackening. Same family, two generations, two procedures that must not be mixed: slackening a Z7X bolt to re-torque it, or skipping the slackening on an early engine, both break the method. Renault 30 M.R.167, folios B-25 and B-37 · Alpine M.R.297, folios 11-6 and 11-7 · Safrane M.R.302, chapter 11.
Two torques far apart, and several details that make the difference between a dry timing case and a leaking one. The oil pump drive sprocket bolts go in with Loctite and only 0.6 m.kg — a small figure on small bolts, easy to overshoot. The timing cover gasket goes on dry; the cover is located by two dowels, and its lower bolts get Loctite. Once it is on, trim the gaskets flush at the upper cylinder head joint faces, so that nothing stands proud under the head. At the front: fit the pulley's oil seal with the Mot. 658 fitting sleeve, oil the pulley's sealing face before sliding it on, put Loctite on the crankshaft thread, hold the crankshaft with the Mot. 592 tool, and lock the nut at 17 m.kg — the Alpine V6 GT, same seal with Mot. 658 and same oiled pulley, tightens its own to 18 daN.m with Loctite Frenbloc, then refits the TDC sensor's holding plate. A pulley refitted dry on its seal, or a nut refitted without thread lock, are the two classic sources of a front-end leak or a pulley working loose. On the head side, when replacing a gasket: two 3 mm rods slid sideways into the centring dowel bores stop the dowels being driven into the block as the head goes on; head gasket new and dry; camshaft stop fork withdrawn far enough not to bind the camshaft, then engaged in its groove and tightened to 1.5 m.kg; camshaft sprocket bolt at 7.5 m.kg and that bolt's blanking plug at 3 m.kg. Renault 30 M.R.167, folios B-35 and B-45 · Alpine M.R.273, folio B-26.
1 - 6 - 3 - 5 - 2 - 4. Z engines manual, folio 10-91.
The manual gives two methods. The second starts with cylinder 1 at distributor TDC — cylinder 5 rockers rocking, mark (A) on the flywheel facing mark (0) on the clutch housing — and works from tables: at that position A1/E1, A2/E3, A4/E6; after one crankshaft turn, A3/E2, A5/E4, A6/E5. A separate table covers bank B, indexed on the rocking rocker. Z engines manual, folios 10-90 and 10-91.
No, it cannot be repaired — it is replaced. Oil enters the centre of the shaft, crosses it, travels between rocker and shaft and reaches the tappet; the thrust washer is fitted notches facing the tappet. Z engines manual, folio 10-32.
Each cylinder bank is set separately. Dwell angle: 76°, which reads 38° on the six-cylinder scale of the diagnostic centre, or 63% on a percentage dwell meter — set on screw C, at cranking speed. Ignition point: 10° ± 1°, at a steady 900 rpm idle, distributor vacuum pipe disconnected. The manual warns twice: re-check the setting after tightening the distributor, and do not touch the dwell angle again once the timing is right. Renault 30 M.R.167, folio C-6.
No, on the catalysed versions: the manual writes « not adjustable » in so many words, for both the speed and the CO. Renault 25 V6 Turbo 205 bhp (Z7U-700): 750 ± 50 rpm. Alpine A610 (Z7X-744): 700 ± 50 rpm. In both cases the figure is checked with the engine warm, between 80 and 100 °C, and CO must not exceed 0.5%. A drifting idle cannot be taken up on a screw: look to the regulating valve, the potentiometer or an air leak. N.T.1558 folio 12-1 · Alpine M.R.297 folio 12-1.
Almost entirely — but not quite, and the difference matters. Both manuals give the same components: Solex single-barrel Ø 55 mm throttle housing, marking 984, Bosch 12 V, 3 bar, 130 l/h pump, solenoid injectors of 2.5 ± 0.5 Ω, fuel filter every 50,000 km, and the same XR25 readings on the load potentiometer — 7 to 13 at idle, 225 to 252 at full load. The pressure regulator does differ: 2.5 ± 0.2 bar at zero vacuum on the Z7U-700, 3.0 ± 0.2 bar on the Z7X-744. Never serve one's value for the other. N.T.1558 folio 12-1 · Alpine M.R.297 folio 12-1.
The turbo is a Garrett type T3 with integral wastegate, set to 0.95 bar ± 30 for an actuator rod travel of 0.38 mm ± 0.02. The pressure actually read at the inlet manifold is lower and — this is the surprise — it falls with engine speed: 0.80 bar ± 50 between 2,000 and 3,000 rpm, but only 0.65 bar ± 50 at maximum speed. A safety switch cuts in on overboost, between 1.10 and 1.20 bar — though the switch's own check page (B-61a) has it closing between 1.0 and 1.1 bar — and the bypass valve (Umleitventil) opens at a vacuum of 0.20 bar ± 20. Alpine M.R.273, D501 update, folios B-49a and B-61a.
On the car, turbo in place, heat shield off — the manual stresses that a turbocharged petrol engine's output depends on this setting. Values for the Z7U 730: check 0.920 to 0.980 bar, setting 0.950 to 0.980 bar, rod travel 0.36 to 0.40 mm. Tool Mot. 1014: an adjustable pressure reducer (1), a 0 to 1.6 bar gauge (2), a zero screw (3) and a bleed screw (4); zero the gauge, back screw 1 and the bleed screw right off, connect hose A to compressed air and hose B to the capsule, close the bleed screw, then wind screw 1 in slowly — easing it slightly steadies the pressure. Check: remove the heat shield and the cooling air hose with its nozzle, disconnect the capsule hose and fit Mot. 1014, dial gauge on the rod, zeroed; raise the pressure until the rod has moved 0.38 ± 0.02 mm and read the gauge. Out of tolerance: a capsule whose rod joint is crimped is replaced complete with its rod; one whose joint is sealed with a spot of paint is adjusted. Setting: check there is no leak between gauge and capsule; hold the wastegate shut by its lever (8), set the sleeve (3) so its hole lines up with the lever pin and fit it; pressure back to zero, gauge zeroed; raise to 0.38 ± 0.02 mm — the reading must equal the setting value; otherwise shorten the sleeve to raise the pressure, lengthen it to lower it; locknut (6) at 0.6 to 0.7 daN.m, a spot of paint on locknut and sleeve — never on the smooth part of the rod. Replacing the capsule: disconnect the turbo's oil feed and return, pull off the hose, remove clip (2), unscrew sleeve (3) and the bolts (4); the capsule must be turned half a turn to come out beside the turbo; new capsule on new bolts, 1.65 to 1.85 daN.m. Safety pressure switch: on Mot. 1014 with an ohmmeter — rising pressure, below 1.0 bar infinite, 1.0 to 1.1 bar 0 Ω; falling, infinite again at about 0.8 bar. The pneumatic hoses are colour-coded: fuel pressure regulator red, dashboard boost gauge white, bypass valve green, safety switch yellow, wastegate blue, manifold pressure sensor orange; the intake uses screw clamps with a plastic bed, and replacements must be the catalogue ones. Alpine M.R.273, D501 update, folios B-53a and B-59a to B-61a.
Because the tank sits far from the main pump. An auxiliary pump, at the front under the tank, feeds the line: 12 V, maximum delivery 15 l/h at 0.45 to 0.55 bar. The main electric pump, under the right rear wing, provides the working delivery: 12 V, 130 l/h minimum at 3 bar. Each has its own filter, with its own interval — auxiliary pump pre-filter every 60,000 km, fuel filter every 45,000 km, and paper air filter every 15,000 km. Filter and main pump both live in the right rear wing: remove the right rear wheel and the protective housing, clamp the hoses with Mot. 453-01; the filter goes back in the flow direction marked on it, the pump with its hoses and its + and − leads as marked on the pump. Air filter: loosen the clamp, remove the strap, lift it out, and on refitting line the intake spigot up correctly with the body side panel. Alpine M.R.273, D501 update, folios B-49a and B-62a.
With a dial gauge, on the actuator rod — tool Mot. 1014 connected to the capsule union. Hold the wastegate closed by its lever, adjust the rod length so its hole lines up with the lever pin, bring the pressure back to zero and zero the gauge. Then raise the pressure progressively: the rod must move 0.38 ± 0.02 mm, then 4 ± 0.05 mm, and the pressure read must then match the table value. Out of tolerance: SHORTEN the rod to RAISE the pressure, lengthen it to lower it — the direction people most often get backwards. Locknut tightened to 0.6 to 0.7 daN.m, then a spot of paint on the locknut and the thread — never on the smooth part of the rod. ⚠️ One internal inconsistency is worth flagging: this first travel is given as ± 0.02 mm on the adjustment page (folio 12-13), but as ± 0.05 mm on the specifications page (folio 12-2) and on the check page (folio 12-11) of the same manual — and ± 0.05 is also what the A610's manual uses, on both its pages. And the explanation is to be found at Alpine: the GTA V6 Turbo (D 501) manual gives ± 0.02 mm on both of its pages. The GTA's Z7U 730 really does carry a tighter tolerance than the R25's Z7U 700 — and folio 12-13's lone figure looks very much like a carry-over from the Alpine manual, just as the A610's chapter 17 reuses the R25's. Technical note 1558, folios 12-2, 12-11 and 12-13.
1,300 mbar, and the check is simple: switch removed, connected to the Mot. 1014, an ohmmeter across its terminals. Below 1,300 mbar, R = 0 Ω; at 1,300 mbar and above, R = ∞ — the circuit opens. ⚠️ Do not transpose to the Alpine GTA V6 Turbo: its switch acts between 1.10 and 1.20 bar. Same function, two thresholds — and above all two opposite electrical logics. The GTA's check procedure is unambiguous: below 1.0 bar, R = ∞; between 1.0 and 1.1 bar, R = 0 Ω; and on the way back down the circuit reopens around 0.8 bar. Where the R25's switch OPENS on overboost, the GTA's CLOSES. A mechanic applying the R25's table to a GTA condemns a healthy switch — and the other way round. Also worth noting inside the GTA's own manual: its specifications page announces a threshold of 1.10 to 1.20 bar where its check page measures 1.0 to 1.1 bar. Technical note 1558 folio 12-13 · Alpine M.R.273 folio B-49a.
Electronically — like the catalysed R25 V6 Turbo's Z7U 700, but the XR25 does not speak the same units. The computer drives a 12 Hz frequency valve — the “SEM” valve — which varies the pressure by bleeding it back to the air filter; it continuously compares the mapped pressure with what the pressure sensor reports. On the XR25, two values are read and must not be confused: # 11 gives the valve's opening ratio (RCO), between 3 and 99%; # 20 gives the correction applied relative to the nominal mapped value, between 0 and 35% ± 1 depending on engine speed and manifold pressure. After a road test, ignition on and engine stopped: insufficient pressure → positive correction, # 20 = 21% ± 1; pressure too high → negative correction, # 20 = 0.0%. A brand-new, never-used computer shows # 20 = 10% ± 1. The R25 V6 Turbo's note describes the same 12 Hz SEM valve and the same # 20, but in milliseconds: a new computer ≈ 65 ms, insufficient pressure 26.16 ms, pressure too high ≈ 0.8 ms. A # 20 read on one car cannot be judged against the other's table. Both engines also keep a wastegate rod set with a dial gauge. Alpine M.R.297, folios 12-8 to 12-10 · Technical note 1558, folios 12-8 and 12-9.
0.10 mm on the inlet, 0.25 mm on the exhaust — more than twice as much on the exhaust side, which runs hotter and expands more. The adjustment follows the head re-torque, itself done cold and at the earliest six hours after a warm engine is stopped. For comparison: the Eagle Premier's V6 has no clearance to set at all, its rocker arms carrying a hydraulic tappet. Alpine M.R.297, folio 11-7.
A Garrett T3 with integral wastegate, and two check points rather than one: 430 ± 30 mb for a rod travel of 0.38 ± 0.05 mm, then 610 ± 30 mb for a travel of 4 ± 0.05 mm. The pressure in the intake manifold, read on the XR25, must be 1,750 ± 10 mb between 2,750 and 3,750 rpm — accelerator floored from 2,000 rpm, in 3rd or 4th — and 1,750 ± 10 mb at the maximum speed of 5,500 rpm, in 2nd or 3rd. ⚠️ That is the pressure in the manifold, not boost above atmospheric: the figure is flat from one end of the range to the other, which is the regulation plateau. The bypass valve (Umleitventil, the turbo's recirculation valve) opens at a vacuum of 200 ± 20 mb. On the R25 V6 Turbo's Z7U-700 the setting is lower for the same travels — 320 ± 30 mb then 480 ± 30 mb — but the manifold pressure is higher: 1,870 mb. Alpine M.R.297, folio 12-2 · Technical note 1558, folio 12-13.
A Garrett T3 with pressure-limiting valve, two check points: 320 ± 30 mbar for a rod travel of 0.38 ± 0.05 mm, then 480 ± 30 mbar for a travel of 4 ± 0.05 mm. The pressure in the manifold, read on the XR25 at full load on a road test, must be 1,870 +50/−10 mbar between 2,750 and 3,750 rpm — full throttle taken at 2,000 rpm and held, in 3rd or 4th — and 1,840 +50/−10 mbar at the maximum speed of 5,500 rpm, in 2nd or 3rd. Unlike the A610, whose figure is flat, this one eases off slightly at the top end. The bypass valve opens at 200 ± 20 mbar — a vacuum taken below the throttle, as its own page (folio 12-10) specifies; the specifications page prints “opening pressure”. The engine's safety switch cuts at a relative pressure of 1,300 +100/−0 mbar. Technical note 1558, folios 12-2 and 12-10.
Cold, 0.10 mm inlet and 0.25 mm exhaust — the same figures as the A610's Z7X 744 fifteen years later, with the Mot. 647 spanner. The manual gives two methods. The first works one head at a time by the rocking method: with the valves of cylinder 1 rocking, set inlet A3 and exhaust E2; cylinder 2 rocking, A1 and E3; cylinder 3 rocking, A2 and E1. The second does both heads at once and is quicker: bring piston 1 to TDC on firing — which is cylinder 5 rocking, with the flywheel's mark A against the 0 on the clutch housing — and set inlet A1, A2, A4 and exhaust E1, E3, E6; then turn the crankshaft one full revolution, which brings piston 1 back to TDC at the start of induction with cylinder 1 rocking, and set inlet A3, A5, A6 and exhaust E2, E4, E5. Lift the cover plate slightly to reach the marks. Alpine M.R.273, folios B-12 to B-14.
A = admission (inlet), E = échappement (exhaust) — the French abbreviations, kept in the drawings of every manual in the Library, whatever the language of the edition. The German edition of the Renault 30's M.R.167 knew exactly how much of a trap that is for its readers, since in German A stands for Auslass, the exhaust: it boxes a warning on the valve-setting page, “ACHTUNG: A = Einlass, E = Auslass”. Read the letters the wrong way round and you set the inlet clearance on the exhaust valves, which is a quarter of a millimetre out on both. The Alpine M.R.273 uses the same convention fifteen years later, with the same tables. Speaking of which: the clearances themselves never moved — 0.10 mm inlet, 0.25 mm exhaust, engine cold, on the 1975 Renault 30, on the Alpine GTA and still on the 1991 A610, all set with the same Mot. 647 spanner. Renault 30 M.R.167, folio B-38 · Alpine M.R.273, folios B-12 to B-14 · Alpine M.R.297, folio 11-7.
To keep the valves away from the pistons while the camshafts are still free. Before fitting the timing, the Renault 30's manual has the crankshaft positioned in two ways at once: keyways pointing upwards, and piston no. 1 standing 15 mm before TDC, “to avoid any contact with the valves”. With no piston at the top of its stroke, a camshaft that turns while its sprocket and chain are being fitted cannot drive an open valve into a piston crown. It is a reflex worth keeping on any PRV: never turn a camshaft with a piston at TDC and the timing disconnected. Renault 30 M.R.167, folio B-31.
Two belts, two sets of figures, measured with the Ele. 346-04 gauge. Alternator / water pump, a ribbed belt: F = 3 mm cold, 3 to 3.5 mm warm, and — this is the useful part — re-tension it only if F exceeds 4.5 mm. Air conditioning compressor, a plain V-belt: 3 to 4 mm cold, 3.5 to 4.5 mm warm. One assembly rule applies to both: “the belt must always be fitted with the tensioner slack”, to avoid overloading the pulley and the belt. A belt fitted over a tensioned tensioner is a belt already damaged. Alpine M.R.273, folios B-23 and B-24.
Yes, with thread inserts, in every tapped hole of the engine — with one exception: the M25 × 1.50 thread of the oil gallery plug on the cylinder block. Z engines manual, folio 10-41.
Solvent S56 for cleaning parts, Décapjoint aerosol for the gasket face, Loctite Frenetanch (1 to 2 drops) on the oil separator screws, Loctite Frenbloc (1 to 2 drops) on the tensioner roller spindle and the flywheel, Loctite Autoform on the flywheel-to-crankshaft face, Rhodorseal 5661 in the corners between head gasket and timing-cover gasket, Autojoint OR AJ66 on the wide-flange timing cover — each with its Renault part number. Z engines manual, folio 10-40.
Yes — and it is counter-intuitive. The Alpine manual is explicit: « above a proportion of more than 60% antifreeze in the coolant, the protective effect decreases ». The correct doses: 35% for protection to −23 °C, 50% for −40 °C. The product the manual names is Glaceol AL type C, and the coolant is renewed every 60,000 km. Measurement is taken with a hydrometer, on coolant drawn from the expansion tank, the manual's tables holding for a coolant temperature of 40 °C. The A610 manual repeats the same page word for word, eight years later. Alpine M.R.273 folio B-21 · Alpine M.R.297 folio 19-4.
It depends on the CAR, not the engine — and the gap is wide. Renault 30: 9.8 litres. Alpine GTA: 15 litres. Same engine family, nearly twice the coolant: the car, its hoses and its radiator count as much as the block. Never transpose a capacity from one model to another. On the Renault 30, engine oil holds 5.5 litres and the circuit is hermetically sealed with an expansion tank, the antifreeze protecting to −30 °C, and −40 °C in countries with extreme climates. M.R.167 folio B-3 · Alpine M.R.273 folio B-21.
There are two, one for the turbocharger, one for the engine bay, and they run constantly at two speeds. As soon as the temperature reaches about 60 °C, they run on 6 volts. Above 90 °C they switch to 12 volts. They drop back to 6 volts when the temperature falls to 80 °C. And after the ignition is switched off they keep running for two minutes — enough to carry the turbo's heat away at a standstill. A fan that never turns at idle is therefore not normal on this car. The ignition chapter's diagrams say which temperature each switch reads. The 60 °C switch (233) reads the oil, under the sump: below 60 °C oil, no fans; above, both run at 6 V through resistor 577 on the heater. The 90 °C switch (574) reads the air in front of the turbo: above it, resistor bridged, 12 V. Ignition off with oil above 60 °C, both run two minutes at 12 V, via delay relay 300 — driven by the oil switch alone. A third switch, 110 °C (575) on the same bracket, only detects engine-bay overheating: it lights the fan-failure lamp (on the right of the instrument panel) and the STOP lamp — as does relay 576 if just one of the two fans fails, open or short circuit. Alpine M.R.273, D501 update, folios B-49a and C-47a to C-49a.
Three independent systems set about limiting the temperature rise in the engine bay once the car stops. Turbocharger bearing cooling: an electric water pump, driven by a delay relay, keeps running for about 12 minutes after the engine and ignition are switched off, circulating coolant through the turbo bearings. Hot air extraction: a funnel-shaped deflector plate in front of the turbo is linked to a separate fan that draws the hot air away. And the main cooling fans: after the engine is stopped, a delay relay keeps them and the hot-air extractor available for about 12 minutes, but they only start if sensor 480 measures 100 °C in the engine bay; the two fans then run in series, at half speed, until the temperature falls to 95 °C or the relay cuts out after 12 minutes. A pump that stays silent after shutdown is therefore no small matter on this car: it is the turbo bearing cooling that is missing. ⚠️ Not to be confused with the Alpine GTA V6 Turbo, whose two fans keep running for two minutes after switch-off: two cars, two arrangements, two durations. Technical note 1558, folios 18-1 to 18-3 and 18-5 · Alpine M.R.273, folio B-49a.
No. The manual puts it in italics: “the joint face must not be re-worked”. The check is made with a steel straight edge and a set of feeler gauges: the maximum allowable distortion is 0.05 mm. Beyond that the head is replaced, not skimmed. That is the price of a wet-liner engine: skimming the joint face would change the liner protrusion, and therefore the sealing — what you gain on one side you lose on the other. Alpine M.R.297, folio 11-5.
No, and the manual says so in three lines that are easy to read past: “the cylinder head gaskets are different. The bulge marked by the arrow is larger on the left head gasket than on the right”. Left is bank A, cylinders 1-2-3. So an engine gasket set is not two identical gaskets, and a single gasket ordered without saying which side is a gasket ordered at random. It is worth checking the bulge against the old one before laying a new gasket on the block — a wrong-sided gasket fits the studs perfectly and only shows itself later, as a coolant passage in the wrong place. Renault 30 M.R.167, folio B-13.
No. The manual closes the question in one sentence: “the ring gap was machined at the factory to the corresponding fitted dimension”. Three rings per piston: a top ring 1.5 mm thick, a compression ring 2 mm, and an oil scraper 4 mm. So the ritual of filing each ring to its bore, which many engine rebuilds call for, has no place here — rings come ready for their liner, and taking a file to them can only open a gap the factory had set. Renault 30 M.R.167, folio B-9.
One sentence holds the whole thing, and the manual prints it as a memory aid: “Merksatz — the collar of the rod foot goes on the side of the “AV” arrow on the piston crown”. Everything else follows from it. All six pistons are laid on the prism block with the “AV” arrow pointing UP. Rods 1-3-5 — the left bank — go on the hot plate collar DOWN; rods 2-4-6 — the right bank — collar UP. Each assembly is then marked so its bank can be told at a glance, because the two are no longer interchangeable. Heating: a 400 W hot plate, small ends flat on the plate, and a neat trick for checking the temperature without a pyrometer — a dab of solder melting at about 250 °C laid on the rod, which tells you when to press the gudgeon pin. On final assembly into the block, the arrow on the piston crown points to the timing case side. Renault 30 M.R.167, folios B-50 to B-53 and B-29.
By shimming each liner with a seat seal chosen by colour, and by respecting one figure above all: the difference in protrusion between the liners of one bank must not exceed 0.04 mm. Measure each liner, compare them, and if the spread is too great, fit the next thinner seal to the liner or liners standing proudest. Four thicknesses, each identified by a colour mark: blue 0.087 mm · white 0.102 mm · red 0.122 mm · yellow 0.147 mm. The measurement goes like this: fit a single liner, with its piston and rod but WITHOUT a seat seal, measure its protrusion with a dial gauge (Mot. 252 base, Mot. 251 holder) on both sides, A and B, keep the higher of the two readings and subtract it from 0.23 mm. The thickness obtained — or the next one down — applies to the seals of every liner in that bank; then repeat for the other bank. The manual's own worked example: protrusion at A 0.10 mm, at B 0.08 mm; subtract 0.10 from 0.23; that gives 0.13; choose a red-marked seal, mean thickness 0.122. At first assembly all the liners of a bank get seals of the same thickness, lugs seated in their groove, and the protrusion is checked again afterwards. With the seat seals in place it must be between 0.16 and 0.23 mm, and as close as possible to 0.23 mm — which is where the 0.23 in the example comes from. Two useful freedoms on reassembly: a new liner may be fitted in any position in the block, and a height difference between the right and left side of a liner is taken up by rotating it in its seat. This is the adjustment the Eagle Premier's diagnosis chart points to when it says a head gasket that blows may be “caused by improper liner protrusion”: on a wet-liner engine, a gasket that fails twice is not a poor gasket. Renault 30 M.R.167, folios B-25 to B-27, B-44 and B-53 · 1990 Eagle Premier service manual, folios 9-9 and 9-10.
Yes, and one at a time. The manual boxes it: “the engine does not have to be removed for this work. Each liner-piston unit can be replaced individually”. Better still, when one or more units of one bank are replaced, neither the timing cover nor the timing parts need to come off. The trick is the Mot. 589 holding tool: fit its holder (S) first, then the dummy bearing (F), and tighten the camshaft sprocket bolt moderately. With the dummy bearing in place, the crankshaft can be turned to bring each big-end cap within reach in turn, without the timing shifting. That is exactly the case the Safrane's manual reserves the dummy bearing for, fifteen years later: it is used only when the crankshaft has to be turned with the head off. And a reminder that sets the budget: the parts department supplied blocks with the oil pump already fitted. Renault 30 M.R.167, folios B-25 and B-47 · Safrane M.R.302, chapter 11.
Yes — and it is a part few people expect on a V6. The head removal procedure calls for taking off, in order: the balancing system's drive chain, then its sprockets, then driving out the shaft to free the balance weight and its key. On reassembly the small pinion of the balancing system is torqued to 2.5 daN.m, and the Mot. 1209 tool is removed at the right moment so that the chain is properly tensioned by its tensioner. The system goes back on at the same time as the rocker arms and the pushrods. Alpine M.R.297, folios 11-1, 11-3, 11-6 and 11-7.
Four, where the catalysed R25 V6 Turbo has three — and the manual lists them by letter. A: a blower forces fresh air through the bonnet ducts to the engine, and blows air through the manifold cover onto the injector tips. B: a second blower extracts the hot air from the turbocharger's heat shield and pushes it outside. C: ducts placed in a pressure zone, which distribute fresh air on the move without any fan at all. D: the electric water pump that cools the turbo bearings — mounted on the right rear wheel arch near the air filter, timed by a delay relay in the accessory computer to 12 minutes, pushing water from the turbo bearings to the expansion tank. On top of that, the main fans run at half speed as soon as the coolant reaches 92 °C after the ignition is switched off. In normal running they cut in above 90 °C and stop again at 80 °C; the blower and the extractor obey a thermal switch set to 90 °C, and likewise run until the temperature falls back to 80 °C. A second switch, set to 110 °C and mounted low on the bracket opposite the turbo, does nothing but earth a warning light when the bay gets too hot. Their 15 A fuse hides between the two rear seat backrests. Alpine M.R.297, folios 18-1, 18-2, 18-8 and 18-9.
From inside the car: it sits in the passenger compartment, in the middle behind the rear seat backrest. First isolate the battery with the battery isolator switch and deactivate the alarm. Fold both rear backrests forward, and remove the four side cross-head screws of the trim between them: the relay plate is now accessible. It is held by three screws — A and B on the fuse holders, C behind the first relay. Then unplug the computer's 35-way connector and remove its three fixing screws. On refitting, check that the relay connectors and the computer's connectors are properly seated. On the same plate, two relays matter for every injection check: 238, the injection locking relay, and 236, the fuel pump relay — the one bridged for the fuel pressure and delivery tests. Alpine M.R.297, folios 17-19 and 17-20.
The manual gives two diagnostic trees. The parts involved: the accessory computer and the main fans' control relay, both in the front passenger footwell (35-way connector, and a 13-way connector behind the housing). After switch-off, the fans only run at half speed in two conditions: during the 12-minute turbo cooling delay, and with coolant above 92 °C. Tree 1 — the electric pump does not run. 12 V at the pump? If yes, check its earth with an ohmmeter (infinite: repair the wiring; 0 Ω: check the winding — infinite, replace the pump). If not: 12 V on terminal 5 of relay 465? Yes — repair the wiring to the pump. No — 12 V on terminal 3 of relay 465? If yes: 12 V on its terminal 1 (otherwise repair the feed from the battery isolator), then earth its terminal 2 — if the pump does not start, replace relay 465; if it does, check the wire between output 17 of the accessory computer and terminal 2 of 465 (sound: replace the accessory computer). If there is no 12 V on terminal 3 of 465: 12 V on terminal 4 of relay 236? Yes — repair the wiring between the two relays. No — 12 V on its terminal 3? Yes — replace relay 236; no — repair the feed from the battery isolator. Tree 2 — the pump runs, the fans do not above 92 °C. The manual notes that the fans run on 12 V as soon as the AC is switched on, and that these symptoms clear relays 236 and 465, the operation and circuit of relays 335 and 336, the fan wiring and the fans themselves. Ignition off, bridge terminals 3 and 5 of relay 57. Fans at half speed? Then 12 V on terminal 2 of 57 (otherwise repair the link to terminal 5 of 465) and earth its terminal 1: fans still off — replace relay 57; fans running — check the wire to output 17 of the accessory computer, or replace it. Fans off with 57 bridged: without 12 V on terminal 3 of 57, repair its feed or replace 57; with 12 V, bridge terminals 3 and 5 of relay 337 — fans still off: check the circuit from 337 to relays 336 and 335; fans running: 12 V on terminal 2 of 337? no — check the link from 57 to 337, or replace 337; yes — check the circuit through thermal switch 248, or replace it. Alpine M.R.297, folios 18-3 to 18-7.
By priming it with oil before the engine fires — the manual's sequence leaves nothing to chance. The turbo comes out with its bracket, which is then separated on the bench. On refitting, three sets of parts must be renewed: the gaskets removed, the self-locking nuts between turbo and exhaust manifold and the self-locking nuts of the exhaust pipe. Then the priming: pour engine oil into the turbo's oil inlet; unplug the three-way connector of the ignition power module and crank until oil comes out at the union; only then start the engine and let it idle for a while so the oil circulation is fully established. Check for leaks, especially at the Bischoff clamps — and do it before refitting the heat shields. Torques: Bischoff clamps 2.5 daN.m; elastic clamps on the hose between compressor and manifold to the intercooler 0.3 daN.m, and the manual names the screwdriver for it (FACOM A 202 B). ⚠️ The same manual prints two other values for these parts: Bischoff clamps 1.5 daN.m and intake manifold 2 daN.m in the cylinder head chapter's table (folio 11-1), against 2.5 daN.m here and 1.25 ± 0.25 daN.m for the manifold on the head at folio 12-17; the extract does not say which prevails. And a note: never run the engine without the air intake system connected. Alpine M.R.297, folios 11-1, 12-16 and 12-17.
The intercooler starts with the battery: disconnect and remove it, then the ABS computer and the battery tray, pull off the inlet and outlet air hoses, remove the screws and take out the intercooler with its bracket. On refitting, three points: the intercooler's position on the air intake duct, the ABS computer's connector pushed fully home, and the air hoses correctly tightened. The turbocharger: remove the rear heat shield with its extraction deflector and the turbo cooling air nozzle, then the heat shield fixed to the turbo; the hard-to-reach screws (5) come out easily with tool Mot. 909-01. Disconnect the exhaust (mind the oxygen sensor — remove it if need be), the air intake duct, the inlet pipe hose, and the oil and coolant supply lines. The oil return hose needs an angled Allen key, H = 30 mm; the turbo nuts come off with a FACOM no. 40 combination spanner modified as the manual draws it (a flat ground on it). Refitting: clean the gasket faces on manifold and turbo; replace the self-locking nuts between turbo and manifold with new ones; renew the oil supply and return seals; pour engine oil into the inlet (4); renew the coolant supply and return seals; unplug the three-way connector of the ignition power module and crank until oil comes out at union (4), then tighten that union, reconnect, and let the engine idle so the oil pressure builds; finally bleed the cooling system and top up. The same oil priming as on the Alpine A610 — plus the coolant circuit the A610's refit does not mention. One oddity to know: the NOTA of the German edition reads, word for word, “never run the engine without the air intake system disconnected” (“abgeklemmtes”), where the A610's manual — and the Alpine GTA V6 Turbo's, on the same procedure — writes “connected” (“angeschlossenes”). Technical note 1558, folios 12-14 and 12-15 · Alpine M.R.297, folio 12-16.
With the turbo's oil lines out of the way first: to reach the capsule, the turbo's oil supply and return lines must be disconnected. Pull off the hose to the capsule, remove the circlip (2) and free the rod (3), remove the bolts (4) and take the capsule out. The catch, boxed in the note: the capsule must be turned half a turn before it will come out past the side of the turbocharger. On refitting, the new capsule goes on with new bolts, tightened to 1.65 to 1.85 daN.m; screw the locknut (5) and the threaded sleeve onto the rod — then set the boost with the dial gauge, as on folio 12-13. Technical note 1558, folio 12-12.
By clearing six things first, then working around the turbo. Before removal: the idle regulation valve's air hoses; the air hoses between compressor and intercooler and between compressor and throttle housing; the complete damper and fuel pressure regulator; the throttle control bracket and linkage; the injection rails; and the three nuts and studs holding the turbo bracket to the manifold. The manifold then comes off — it is held to the cylinder head by four bolts. On refitting, new gaskets are compulsory, and since refitting is awkward the manual advises tilting the turbo slightly: free the exhaust from the catalyst inlet and release the two Bischoff rings — on the left directly at the manifold outlet on the head, on the right midway between the two connecting hoses. Once the manifold is refitted and tightened, refit its studs on the turbo bracket and renew the bolts between exhaust pipe and catalyst. Then tighten in this order: turbo bracket on the manifold, Bischoff clamps, exhaust pipe. Check the fuel supply and return lines of the rails, the connectors and the spark plugs, and that the exhaust does not leak. Manifold on head: 1.25 ± 0.25 daN.m — while the table of the cylinder head chapter gives 2 daN.m (folio 11-1). And a line marked IMPORTANT: after any major work such as removing the turbo or the manifold, check the orientation of the bypass valve — its union must face the vacuum capsule. Alpine M.R.297, folios 11-1 and 12-17.
One side at a time, and the two sides are not the same job. First the intake manifold cover. Left rail: disconnect and remove the idle regulation valve's air hoses at the throttle housing; unplug the injector and spark plug connectors; unscrew the fuel supply lines at the rail; unscrew the fuel pressure regulator bracket; free the plastic ventilation duct over the injectors; remove the two bolts holding the rail to the manifold, and lift out rail and injectors together. Right rail: first remove the light-alloy air pipe between compressor outlet and intercooler; then the plugs and injectors, the ventilation duct, the fuel unions and the two rail bolts — the manual notes that a little give in the elastic air hoses helps. On refitting, check that the O-rings (10) and the protector (11) of each injector are undamaged, and renew the O-rings if need be: part 77 01 030 449, fitted new and lubricated (Molykote 33 Medium, for example). Torques of the fuel lines on regulator, damper and injectors: light-alloy line 1.3 to 1.5 daN.m, steel line 1.8 to 2.0 daN.m — then check the whole fuel system for leaks. Alpine M.R.297, folio 13-7.
Fluid: Dexron II, 0.7 litre. Filling: fill the reservoir completely; turn the steering gently both ways; top up; start the engine and turn the steering gently both ways to full lock; top up to the upper mark of the dipstick. Always through a funnel with a 15/100 filter, so nothing gets into the reservoir. Pressure check — tools: hose clamps Mot. 453-01, gauge Fre. 1085 or Fre. 244-04, and the non-metric union Dir. 803. Remove the right front wheel and the front right shield; clamp the pump's low-pressure hoses — the manual places the pump next to the fuel tank; unbolt the pump bracket and ease the pump and bracket out downwards; unscrew the high-pressure line (catch the fluid) and fit Dir. 803 between hose and pump; connect the gauge, remove the clamp, bleed the gauge line; fill the pump and run the engine. Readings: wheels straight, 0 to 3 bar; wheels on full lock, 85 bar maximum (+0 / −5). And a time limit: the measurement must not last more than 2 minutes, otherwise the fluid temperature rises too far. Line union torques: Ø 16: 2.5 daN.m, Ø 18: 3 daN.m. Alpine M.R.297, folios 13-9 to 13-11.
Fluid: Elf Renault Matic D2 or Mobil ATF 220; 1.1 l with a separate reservoir, 0.7 l with a reservoir built into the pump. Top up to three-quarters through a 15/100 filter, start the engine and turn the wheel gently lock to lock, top up and check for leaks; separate reservoir — fluid level with the rim of the filter sleeve; integral reservoir — FULL COLD mark cold, FULL HOT warm. Pressure, V6 engine: clamp the pump's low-pressure hose with Mot. 453-01, disconnect the high-pressure pipe (fluid will run out), fit the metric-thread union Dir. 803 between pipe and pump, connect gauge Fre. 1085 or Fre. 244-04, remove the clamp, top up and run the engine. Wheels straight, at any engine speed: no more than 5 to 7 bar. Wheels held on full lock: 86 to 93 bar maximum — not for long, the fluid overheats. Reading the results — the commonest complaint is lack of assistance: straight ahead, pressure too high at idle → faulty valve; pressure too low when accelerating → faulty regulator. On full lock, the difference between one side and the other must not exceed 5 bar: too low with the needle wavering → faulty regulator; too low with a steady needle → slack drive belt, faulty valve or internal leak in the ram; a difference between the two sides → faulty valve. Afterwards, clamp the supply again, remove Dir. 803 and the gauge, reconnect the pipe, remove the clamp and top up. Beside the Alpine A610's pump, the figures move both ways: 0 to 3 bar straight ahead and 85 bar (+0/−5) on lock there, 5 to 7 and 86 to 93 here. Safrane M.R.302, chapter 13 · Alpine M.R.297, folio 13-11.
Three — one fewer than the A610 that replaced it, and the missing one is the electric water pump for the turbo bearings. A: a blower pushes fresh air through the bonnet ducts to the engine. B: a second blower extracts the hot air from the turbocharger's heat shield and sends it outside. C: ducts set in a pressure zone, which distribute fresh air on the move with no fan at all. Both blowers are switched by a thermal switch: they run permanently on 6 volts from about 60 °C, go to 12 volts above 90 °C, drop back to 6 volts at 80 °C, and keep running two minutes after the ignition is switched off. ⚠️ The manual adds a NOTA that is easy to skip and expensive to ignore: effective cooling of the turbocharger and the engine depends on ducts A and C being correctly aligned and their sleeves being in good condition. A split sleeve or a duct left out of line after a repair does not show on any gauge — it simply stops cooling. Alpine M.R.273, D501 update, folios B-49a and B-50a.
Through an oil separator fitted with a calibrated T-piece, and the two branches are not the same size. A goes to the inlet manifold, Ø 2 mm — the small one, which works on manifold vacuum, that is off boost. B goes to the intake duct between the air filter and the turbocharger, Ø 8.5 mm — the large one, which takes over under boost, when the manifold is no longer in depression. The calibration is the point: replace either branch with a length of plain hose of the wrong bore and the engine either draws oil mist into the inlet or stops breathing at all. The oil filler neck is on the same separator. Alpine M.R.273, D501 update, folio B-54a.
Because the tank is sealed and vented through its own system, not through the cap — so the cap's seal must be compressed to a set amount and no more. Hence the torque limiter built into it: it clicks instead of letting you crush the seal. The unleaded cap adds two things: a filler opening of smaller diameter, so a leaded pump nozzle will not go in, and a flap valve that closes the opening. A sticker in the front compartment repeats the instruction. It is the mirror image of the Alpine GTA, whose tank breathes through its own vent and whose cap therefore has no vent hole at all: on both cars, a cap from another model is the wrong part. Alpine M.R.297, folio 19-13 · Alpine M.R.273, folio B-28.
Upwards, out of the front compartment. First cut the battery with the isolator switch at the front left. Remove the spare wheel, then the five bolts of its carrier and the carrier. Remove the tank's air inlet connected to the two non-return valves, then the plastic protective housing on the tank, and disconnect the fuel gauge sender. Under the car: drain the fuel by unscrewing one of the two fuel lines from the tank, then unscrew the second. The tank comes out from above — but plug the fuel outlets or fit hoses to them first, so that no fuel runs into the front compartment while it is lifted out. On refitting, check that the fuel lines are properly tightened and the sender's connector correctly seated. Alpine M.R.297, folio 19-12.
Four, and the first is the one people forget. The primary pipe is held to the turbo by a three-hole flange and three nuts, locked by a sheet-metal tab — and “every time the pipe is removed, this lock must be replaced”. Between the pipe and the converter, the seal is a Metex ring. The sprung joint carries spacer sleeves that set the spring tension: tighten the nuts until the washers bear on the spacers, no further. And three standing rules: the exhaust must be perfectly gas-tight between cylinder head and converter; any gasket that has been removed must be replaced; and the converter must not take any knock or blow during removal and refitting — it destroys the inside. Manifolds and cross-pipes have their own order: fit and fix the central union (A) first; fit the manifolds (B) with new gaskets, bolts snug but not tight; fit and align cross-pipes (C) and (E), minding the clamp positions; tighten progressively to 2.5 daN.m; then run the engine for about a quarter of an hour and tighten clamps (D) to 2.5 daN.m without slackening them first. Self-locking nuts that were undone are always renewed — their thread is damaged each time. And cross-pipe (E) comes in four lengths, identified by colour: yellow 134.5 mm, blue 136.5, white 138.5, green 140.5 — pick the one for the version. The Alpine A610's manual prints the same sequence, the same torques and the same four lengths; its flange lock plate, it adds, must be cut open to slip over the pipe. The Alpine GTA V6 Turbo keeps the sequence but not the torques: fixings 0.8 to 1 daN.m progressively, then clamps (D) retightened warm to 1.3 daN.m after a quarter of an hour, without slackening; to change its primary pipe, remove the turbo heat shield, the side shield and its holder and the rear left air duct spigot, free the left manifold joints, and take the pipe out rearwards. Technical note 1558, folios 19-4 and 19-5 · Alpine M.R.297, folios 19-8 and 19-9 · Alpine M.R.273, D501 update, folios B-64a and B-65a.
Four, and two of them work against intuition. Tighten the joints in order, starting at the manifold and finishing at the silencer — never the other way, or the line is aligned from the wrong end. Position each clamp so that its clamping face sits squarely on the slotted pipe ends and its opening falls midway between two slots. Respect the clamp bolt torque: Ø 8 mm bolts, 2 daN.m — and no more, “to avoid deforming the pipes and clamps, which could in turn cause a leak”. Overtightening a clamp is the classic way to make it leak. And the flange joint, held by compression springs and a thermo-elastic seal: “replace the thermo-elastic seal after every intervention and tighten so that the coils are touching — do not loosen again”. Here the springs go coil-bound, which is not the case on the catalysed R25 V6 Turbo, whose joint carries spacers and is tightened only until the washers bear on them. Same car, two exhausts, two methods. M.R.249, NT 1205 E supplement, page 14 · Technical note 1558, folio 19-5.
The copper washers, every time. For the pump, the manual says it without qualification: “systematically replace the copper washers at every removal” — a reused copper washer has already been crushed to shape and will not seal again. Two more points on the same job: clamp the hoses with the Mot. 453-01 pliers either side of the pump before removing it, and respect the polarity of the pump's electrical supply on refitting — a pump wired backwards turns the wrong way and delivers nothing. The fuel filter, for its part, sits in the engine bay, mounted horizontally on the left suspension turret. For the oxygen sensor: on refitting, coat its threads with an anti-seize compound to specification MIL A 907B. It is not optional on a part screwed into an exhaust that cycles between cold and several hundred degrees: without it, the next removal strips the thread in the pipe. M.R.249, NT 1205 E supplement, page 26.
Because it is a single unit. On the X54 vehicles there is no joint between the catalytic converter inlet and the silencer outlet — the whole line is one piece, the 4×4 excepted. Replacing one element therefore means cutting the pipe, with tool Mot. 1199, and at a place the manual defines precisely: two cutting areas exist, between the converter and the intermediate silencer and between the intermediate and final silencers. The method is simple and unforgiving: the two marks P1 and P2 are 90 mm apart, you cut on the centre line D between them, and P1 and P2 then serve to position the after-sales sleeve. Cut anywhere else and the sleeve has nothing to locate on. The 4×4 is the exception for a physical reason: the final drive makes it impossible to get tool Mot. 1199 into place, so that car leaves the factory with a sleeve and two collars already fitted — a collar used for this purpose only, on this exhaust, fitted in production. The cut: slacken the chain of Mot. 1199, wrap it round the pipe and hook it on, then tighten the screw while swinging the tool round the pipe — without overtightening, or the pipe deforms. The after-sales sleeve: set it on the original pipe first and close the collar gently; the pipe must be fully against the lugs inside the sleeve; fit the new section; a little exhaust mastic on the sleeve's inner ring prevents leaks (77 01 421 161); the tightening bolt goes at the bottom of the pipe; nut at 2.5 daN.m — correctly tightened, the groove on the nut is no longer visible. Three sleeve diameters: Ø 50 mm J7R-J7T 8-valve, Ø 55 mm J7R-J7T 12-valve, J8S and Z7X, Ø 60 mm S8U. A collar once fitted is never reused. At the front, the downpipe's Metex ball joint: its bolts carry stops that set the spring tension — tighten to the stop; every seal removed is renewed, especially at the converter flange. Safrane M.R.302, chapter 19.
More than on any other PRV in the Library. Besides the engine, the radiator and the heater matrix, it carries a coolant/engine-oil heat exchanger, an electric water pump alongside the belt-driven one, and the turbocharger itself in the circuit. The control side is just as dense: a double thermostat with a double function, a bleed screw, and a two-stage thermal switch. One figure to know before buying a cap: the valve on the “hot” expansion tank is blue, set to 1.6 bar — on an Alpine GTA the cap is a different setting, and a cap is not a universal part. Technical note 1558, folio 19-1.
Oil pressure, measured with the Mot. 836-05 gauge at 80 °C: a minimum of 2 bar at 900 rpm and 3.5 bar at 3,000 rpm. Consumption: “an engine oil consumption of one litre per 1,000 km may be considered normal”. And the manual gives the protocol that settles an argument, safeguards included: engine at operating temperature, dipstick and filler cap removed, drain and at least 15 minutes' draining time; the drain plugs are refitted and marked with paint across both the plug and the sump, so that at the next check you can see whether they have been touched in between; the exact quantity is measured with a measuring glass — 7.5 litres for a Z7X — and the filler cap is sealed. The car comes back at 1,000 km, the plugs and the seal are checked intact, and the oil recovered is measured again under the same conditions. Alpine M.R.297, folios 10-5 and 10-6.
In four situations, and the Safrane's manual gives a separate figure for the V6 each time. Thermal protection: the compressor is not engaged above 120 °C of coolant. Performance protection: at full load below 3,000 rpm, the compressor is cut out for 20 seconds — the V6's threshold is the lowest of the range, against 4,000 rpm on the 8-valve and 4,500 on the 12-valve. Starting: when the starter has been used and the car has moved off, clutch engagement is delayed 10 seconds on the V6, twice the 5 seconds of the four-cylinders. Over-revving: the clutch is cut at 6,000 rpm to avoid damage from centrifugal force. And one anticipation rather than a refusal: at idle, engagement is prepared for by raising the idle to 900 rpm. So air conditioning that stops working when pressing on, or refuses to start for ten seconds, may be behaving exactly as designed. Safrane M.R.302, chapter 17.
Yes — and it asks it to reduce the engine braking. The reason is a real one on a four-wheel-drive car: “under very poor adherence conditions and high resistance to engine torque (the transmission is braking the engine), the wheels may lock despite the ABS reducing the pressure on the brakes to zero”. Brakes released and wheels still locked — because it is the engine holding them. So the ABS computer sends a signal, under five conditions: speed above 24 km/h, deceleration below 3 m/s², stop signal active, a gear engaged and the clutch pedal released. The injection computer accepts it under three more: accelerator not depressed, speed above 20 km/h, engine above 1,000 rpm. It then drives the idle speed regulation valve in the opening direction, its duty cycle set to match the deceleration. A 1992 saloon using its idle valve as a traction aid — and only on the 4×4. Safrane M.R.302, chapter 17.
Three calibrated parts that no catalogue photograph will show you, and one figure to check before buying a cap. The circuit carries a restriction Ø 3 mm, a by-pass Ø 8.5 mm and a nozzle Ø 22 mm, besides the engine, the radiator, the heater matrix, the water pump, the thermostat, a bleed valve and a temperature switch. The expansion bottle is a “hot” bottle with permanent degassing, and its valve is set at 1.2 bar. Set that beside the catalysed R25 V6 Turbo, whose “hot” bottle valve is blue and set at 1.6 bar: four tenths of a bar apart, on two cars of the same era and the same engine family. A cap is not a universal part, and fitting the higher-rated one “to be safe” raises the pressure the whole circuit has to hold. Filling: bleed screws open, fill through the bottle, close each screw as soon as liquid comes out in a constant jet, then run at 1,500 rpm and set the level by overflow after about four minutes. Bleeding: run 10 minutes at 1,500 rpm, until the fan cuts in — the time the automatic degassing needs — and check the level is near Max; in capitals, never open the bleed screws with the engine running, and retighten the expansion bottle cap once the engine is warm. Sealing test (kit M.S. 554-05): replace the bottle valve with adaptor M.S. 554-01, warm the engine and stop it, pump up to 0.1 bar below the valve setting (the A610 and GTA manuals say 0.1 bar above) — the pressure must not drop; decompress slowly and refit the valve with a new seal. Valve test: a valve that has let liquid through is replaced; on adaptor M.S. 554-06, the pressure must settle at the setting, ± 0.1 bar — brown plastic valve 1.2 bar, blue plastic valve 1.6 bar. Antifreeze (Glaceol AL type C): 35 % for −23 °C, 50 % for −40 °C, and protection falls again above 60 %; checked with hydrometer 778A or a refractometer, the table values being valid for liquid at 40 °C. The manual's example: a 6-litre circuit reading −15 °C needs 0.7 l of mixture replaced by pure antifreeze to reach −23 °C, 1.9 l to reach −40 °C. Safrane M.R.302, chapter 19 · Technical note 1558, folio 19-1.
A thermostat that opens far later than the rest of the range, and a circuit half as big again. The Z7X thermostat starts opening at 84 °C and is fully open at 115 °C, travel 7.5 mm. The Safrane's four-cylinders — J7R, J7T and the J8S diesel — use one that starts at 73 °C and is fully open at 85 °C, same 7.5 mm travel. Eleven degrees later to crack open, and thirty degrees later to be fully open: a four-cylinder thermostat will drop into the same housing and run the V6 far cooler than it was designed to. Coolant capacity follows the same logic: 10 litres on the Z7X against 7 on the J7R and J7T and 7.2 on the diesel. And set beside the rest of the family, the figure says again that the circuit belongs to the car, not to the engine — 9.8 litres on the Renault 30, 15 litres on the Alpine GTA, 10 on the Safrane, for the same V6. Coolant: Glaceol AL type C, and the manual specifies coolant only — protection to −23 °C for hot, temperate and cold countries, −40 °C for very cold ones. Safrane M.R.302, chapter 19 · Renault 30 M.R.167, folio B-3 · Alpine M.R.273, folio B-21.
At 80 °C, with the Mot. 836-05 gauge: 2.2 bar at 900 rpm and 4.4 bar at 4,000 rpm. Worth setting beside the A610's Z7X, whose figures are given at different speeds — 2 bar at 900 rpm and 3.5 bar at 3,000 rpm: the two engines cannot be compared point for point, and a pressure read at 3,000 rpm on a Z6W is measured against nothing in the manual. Oil consumption is judged by the same yardstick on both: one litre per 1,000 km may be considered normal. And the Z6W figures do not date from the GTA: the 1975 Renault 30 gives exactly the same, 2.2 bar at 900 rpm and 4.4 bar at 4,000 rpm at 80 °C — measured there with the Mot. 654 union screwed in place of the pressure switch and the Mot. 73-01 gauge. Alpine M.R.273, folios B-15 and B-16 · Alpine M.R.297, folios 10-5 and 10-6 · Renault 30 M.R.167, folio B-60.
With four precautions, and the first two decide whether the pump is worth rebuilding at all. If any part of the oil pump is damaged, the complete pump is replaced: “only the relief valve parts are available”. So an oil pump is inspected — its parts and their seat in the block, the pump housing — rather than overhauled piece by piece. On reassembly, make sure the relief valve piston is not fitted the wrong way round: reversed, it no longer regulates. Fit the driven gear into the housing, then the cover, and tighten its four screws while turning the drive flange so the gears cannot bind. And the instruction the manual underlines, because an engine started with a dry pump runs its first seconds without oil: to have the pump working immediately after refitting, remove the oil filter and pour engine oil in through the bore (A) with an oil can. The pump sprocket bolts and the lower timing cover bolts go in with Loctite; the pulley nut to 17 m.kg, crankshaft thread with Loctite. Renault 30 M.R.167, folio B-59.
In two stages with the MS.554 tester, and the valve's rating is written on the valve itself. Leak test: replace the radiator cap with the tester's adapter, open the heater tap fully, bring the engine up to temperature and stop it. Then clamp the hose between radiator and expansion tank with Mot. 453 — this takes the expansion valve out of the circuit — and pump to 0.9 bar, the start of the gauge's red zone. The pressure must hold steady; if it falls, there is a leak. Valve test: remove the clamp, build 0.9 bar again and stop pumping: the pressure must drop to the value marked on the expansion valve, to within ± 0.1 bar. The marking is in millibars — the manual's example: 815 mbar = 0.815 bar. Before disconnecting the tester, release the pressure by unscrewing the expansion tank cap. Note the difference with the later cars: the Renault 30 has a heater tap, which the Alpines and the Safrane do not. The A610's manual uses the same method with two further points: pump to 0.1 bar above the valve's opening pressure, then, once the pressure is released, refit the valve with a new seal; and “an expansion tank valve that has let coolant through must always be replaced”. The A610's is blue plastic, rated 1.6 bar, ± 0.1 bar. The Alpine GTA follows the A610 — adaptor M.S. 554-01 in place of the valve, pump to 0.1 bar above the setting, a brown valve at 1.2 bar — but the Safrane's manual, with the same kit, has you pump to 0.1 bar below the setting: two opposite instructions for the same job, and none of the manuals says why. Renault 30 M.R.167, folio B-62 · Alpine M.R.297, folio 19-2 · Alpine M.R.273, folio B-20 · Safrane M.R.302, chapter 19.
With the expansion tank raised and two bleed screws open. The circuit, the manual's D 503 diagram, includes the engine, the front radiator, a “hot” expansion tank with permanent degassing, the heater matrix, an oil cooler, the turbocharger, the water pump, the thermostat, a thermal switch for the fans, the electric pump that cools the turbo, and a thermal switch that both signals overheating and switches the electric pump on. There is no heater valve: coolant flows through the heater matrix all the time and helps cool the engine — hence, in capitals, DO NOT CLAMP THE HOSES. Filling: check the drain plugs are tight; open the two bleed screws — one on the turbocharger's coolant pipe, one on the front radiator; unclip the expansion tank and fix it as high as possible; fill through the tank; close each bleed screw as coolant flows from it; level at MAXI, cap on. Bleeding: run the engine at 1,500 rpm until the fans cut in; check and top up once cold. NOTA: never open the bleed screws with the engine running. Refit the tank without kinking its hose. Alpine M.R.297, folios 19-1 and 19-3.
With a multimeter, not a pressure gauge — the only engine in the Library checked this way. Its oil pressure sender is electrical, and its resistance is inversely proportional to the pressure. Unplug the sender's connector, fit the extension of tool Mot. 843 to it, and read between the extension and earth. The manual's table, taken at ambient temperature on rising values: 0 bar → 270 ± 15 Ω, 4 bar → 108 ± 8 Ω, 8 bar → 0 to 30 Ω. Which means a warning light staying on is not necessarily a pressure problem: on this engine the sender is a variable resistor and can be measured, not just believed. Elsewhere in the family the check is mechanical — Mot. 836-05 gauge at 80 °C, 2.2 bar at 900 rpm and 4.4 bar at 4,000 rpm on the GTA's Z6W, 2 bar at 900 and 3.5 bar at 3,000 on the A610's Z7X. Safrane M.R.302, chapter 10 · Alpine M.R.273, folio B-15 · Alpine M.R.297, folio 10-5.
They are calibrated, they differ from car to car, and the manuals ask you to check their conformity, not just their cleanliness. On the Safrane's Z7X: downstream rebreathing pipe jet Ø 1.7 mm, upstream pipe jet Ø 6.5 mm, taken off the front bank towards the intermediate manifold and the air filter. On the Alpine V6 Turbo: the oil separator's calibrated T-piece gives Ø 2 mm to the inlet manifold and Ø 8.5 mm to the duct between air filter and turbocharger. On the Alpine A610: an air correction jet of Ø 1.5 mm after the non-return valve, and a Ø 5.5 mm calibrated drilling in the union. On the 1986 Renault 25 V6 injection: a double system, before and after the throttle, with a Ø 2.75 mm calibration. On the Renault 25 V6 Turbo: Ø 2 mm towards the intake manifold side and Ø 6.5 mm towards the turbocharger. Five installations, seven different bores, and no two set-ups alike — the R25 V6 Turbo takes the Alpine V6 Turbo's Ø 2 but the Safrane's Ø 6.5 — the Safrane manual's NOTE is explicit: “the rebreathing circuits must be maintained in good condition. Check the cleanness of pipes and the conformity of jets”. A jet replaced by a plain length of hose is an emission control system that no longer meters anything. Safrane M.R.302, chapter 14 · Alpine M.R.273, D501 update, folio B-54a · Alpine M.R.297, folios 14-1 and 14-2 · N.T.1150 annexed to M.R.249, page 3 · Technical note 1558, folio 14-1.
The manual gives the full index → vehicle table, with compression ratio, bore, stroke and capacity: Z7V 2,664 cc (88 × 73, CR 9.2) · Z7U 2,458 cc (91 × 63, CR 8.6 or 8) · Z6W and Z7W 2,849 cc (91 × 73, CR 9.5 or 8.8) · Z7X 2,975 and 2,963 cc (93 × 73 and 93 × 72.7, CR 7.6 or 9.6). On the engine, the type is read at A and the homologation letter at B. Z engines manual, folios 10-8 and 10-9.
Yes, a printing slip, and it is worth knowing. Its ignition page (page 63) gives the B29A's engine as a « Z7X 702 ». But the specifications page of the same document (page 4) gives six cylinders, 2,849 cc, bore 91 and stroke 73, index 702: those are the Z7W's dimensions. The Z7X is the 3-litre — 2,963 or 2,975 cc, 93 mm bore. The B29A's engine is therefore a Z7W 702, and the « X » on page 63 is a typesetting error. This is why a figure is always cross-checked on two pages before being repeated. M.R.249, NT 1205 E supplement, pages 4 and 63 · Z engines manual, folio 10-35.
No — three indices for one and the same B 298 body. Z7V A 708 for the manual gearbox, Z7V A 709 for the automatic, and Z7V 711 for the Swiss automatic. And the difference is not just a letter: the first two get the side-mounted air filter, the modified crankcase breathing circuit and idle regulation; the Z7V 711 has none of the three. In other words, on a 1986 R25 V6 injection the index tells you what equipment to look for under the bonnet — and there is no idle regulating valve to diagnose on a 711. N.T.1150 annexed to the M.R.249, its page 2 (page 69 of the PDF).
Vehicle B29G, engine Z7U index 700: bore 91 mm, stroke 63 mm, 2,458 cc, compression ratio 8/1, manual gearbox. Note the stroke: 63 mm against the 73 mm of the Z7W and the Z7X — the 2.5 turbo is a short-stroke engine, and that alone rules out swapping crank parts between families. Injection is Bendix multipoint with idle regulation, ignition fully electronic with knock sensor. The computer is a Bendix S 101 716 101, mounted in the engine bay, diagnostic code 107.3. Idle is 750 ± 50 rpm at 80-100 °C and CO 0.5% maximum, both marked “not adjustable”. Fuel: 95 RON unleaded Eurosuper. Catalytic converter C 18 Zeuna Augsburg under the floor, air filter every 20,000 km, fuel filter every 50,000 km, Rochester canister. Plugs Eyquem 805 L JSP, gap 0.65 ± 0.05 mm — where the A610's Eyquem FC 82 LS 3 is not adjustable. Bosch oxygen sensor: at 850 °C, ≥ 625 mV rich, 0 to 80 mV lean. Technical note 1558, folios 12-1 to 12-3.
Two engines that share only their bore. D 500 — Z6W A 700: 2,849 cc, bore 91, stroke 73, compression ratio 9.5, the carburettored atmospheric V6. D 501 — Z7U 730: 2,458 cc, bore 91, stroke 63, compression ratio 8.6, the injected turbo. Same bore, ten millimetres less stroke and a whole point of compression less — a turbo engine is not a detuned atmospheric one. ⚠️ And the page carries a warning in capitals that matters more on this car than on any other: “the designation right and left for the cylinder banks and camshafts is understood as seen in the direction of travel”. On a mid-engined Alpine, standing at the back looking at the engine puts you the wrong way round, and “right bank” then means the one on your left. The manual also points the reader to the Mot. Z (E) workshop manual and technical note 1066 for the engine work itself. Alpine M.R.273, D501 update, folio B-2a.
The LEFT one — also called bank A. The Renault 30's M.R.167 states it in one sentence and draws it: “cylinders 1-2-3 form the left bank, also called bank A; cylinders 4-5-6 the right bank, or bank B”. It matters more than it looks, because every per-bank figure in the manuals is keyed to those letters: the valve timing, for one, is not the same on both sides — bank A opens the inlet 9° BTDC, bank B 7°. ⚠️ And left and right are the car's, not yours: the Alpine manual spells it out in capitals — “the designation right and left for the cylinder banks and camshafts is understood as seen in the direction of travel”. On a mid-engined GTA, standing behind the car to look at the engine puts you the wrong way round, and bank B is then the one on your left. Renault 30 M.R.167, folios B-8 and B-11 · Alpine M.R.273, D501 update, folio B-2a.
No — each one drives something the other does not. The Renault 30's manual says it in one line: “the camshafts of the two banks are different”. The left bank's camshaft, bank A (cylinders 1-2-3), carries the eccentric that drives the mechanical fuel pump. The right bank's camshaft, bank B (cylinders 4-5-6), carries the drive gear for the ignition distributor. So a camshaft is ordered for a bank, not for an engine, and swapping the two is impossible without leaving the engine with no fuel pump drive or no distributor. The same holds on the Eagle Premier's 3.0 L, whose left and right camshafts are told apart by their lobes. Renault 30 M.R.167, folio B-12.
No, on one page — and it is worth knowing before you follow it. Folio 17-2 of the A610's M.R.297 is headed “Engine Z7X 744”. Two pages later, folio 17-3 opens the injection chapter with “the Bendix multipoint injection system of engine Z7U 700” — the Renault 25 V6 Turbo's engine and supplier, on a manual for the Alpine A610. The specifications chapter of the same manual (folio 12-2) gives a Siemens S 101 717 101 computer. The chapter was plainly adapted from the R25 V6 Turbo's manual and that opening paragraph was not corrected. That it is the A610's own chapter can be proved from its figures: its folio 17-17 gives a coolant sensor of 3,050 to 4,050 Ω at 20 °C, where folio 17-17 of the R25's technical note 1558 gives 283 to 297 Ω. Same folio number, two manuals, two cars. When a manual disagrees with itself, the pages carrying values are the ones that describe the car. Alpine M.R.297, folios 12-2, 17-2, 17-3 and 17-17 · Technical note 1558, folio 17-17.
Cover 235 CP 6500, driven plate 235 mm diameter, thickness E = 7.7 mm, 21 splines. A single dry plate with a diaphragm spring, a torsion-damped hub, and a self-centring guided ball release bearing permanently in contact with the diaphragm — so it turns whenever the engine does. One detail sets this car apart: the flywheel and the pressure plate have a conical profile, “for optimum clutch operation”. And the pedal has an assistance unit — a housing with a compression spring fitted between the clutch pedal and its bracket, which holds the pedal against its upper stop at rest and helps past the over-centre point. Gearbox: UN1 018, with a reverse-gear engagement aid to stop it graunching. Technical note 1558, folios 20-1 and 21-1.
Vehicle B544, engine Z7X, suffix 722 or 723: bore 93, stroke 73, 2,975 cc, compression ratio 9.6 — a full point and a half above the 8.6 of the GTA's turbocharged Z7U. Gearboxes PK1 and PK7 manual, AD8 automatic. Injection multipoint Siemens with richness regulation, ignition M.P.A. with a knock sensor. Idle 700 ± 50 rpm between 80 and 100 °C and CO 0.5% maximum, both marked “not adjustable”. Fuel: Eurosuper lead free 95, and a line worth knowing — minimum permitted octane rating: 91. Fuel pump in the tank, 12 V, 3 bar, 80 l/h; pressure regulator 3 ± 0.2 bar at zero vacuum, 2.5 ± 0.2 bar under 500 mbar. Idle regulating valve Hitachi AESP 207, single winding. Three computers, all Bendix: S101 722 101 for the manual 4×2, S101 722 102 for the manual 4×4, S101 722 201 for the automatic. Air and water sensors Bendix, NTC type. Oxygen sensor NGK, heated: at 850 °C, 625 to 1,100 mV rich, 0 to 80 mV lean. Three-way converter marked C20, under the floor. Safrane M.R.302, chapter 12.
When refitting a head: run all the bolts down, tighten them to 6 m.daN in sequence to crush the gasket, then slacken, pre-tighten to 2 m.daN and apply a 115° angular tightening. The re-torque after a gasket change (between 500 and 1,000 km) repeats those last three steps, with the engine cooled for at least 6 hours — bolt by bolt, in sequence, with the Mot. 50 wrench then the Mot. 591-01 angle tool. The manual allows the hurried variant: after only one hour of cooling, tighten to 3.5 m.daN before the angle. A310 2700 VA repair guide, folios B-6a and B-23.
No. The guide is categorical: the permissible distortion of the head face is 0.05 mm, and “no skimming allowed”. Beyond that, the head is replaced. The two figures that go with it: head height 110.87 ± 0.15 mm, chamber volume 53.8 ± 0.6 cc, with a maximum difference of 0.6 cc between two chambers on the same head. A310 2700 VA repair guide, folio B-6a.
Not the original PRV — and the A310 guide puts figures on it, for a production car. For a reference clearance of 0.7 mm at the valve stem: left bank 9° / 45° / 45° / 9°, right bank 7° / 43° / 43° / 7° (opening advance and closing retard, intake then exhaust). Valve lift follows: 8.3 mm on the left, 8.17 mm on the right. These are exactly the figures of the 1976 SAE 760110 paper, a consequence of the three shared-crankpin crankshaft. The asymmetry disappears with the split crankpins of the Z7U-730, quoted at 8° / 40° / 40° / 8° on both sides. A310 2700 VA repair guide, folios B-7 and B-8.
No, and it is a classic reassembly mistake. The camshafts are different: the left one carries the fuel-pump drive eccentric, the right one the distributor drive gear. The head gaskets differ too: the left one has a larger relief. Naming reminder: cylinders 1-2-3 form the left bank, group A; cylinders 4-5-6 the right bank, group B. A310 2700 VA repair guide, folio B-16.
By colour. The base seals come in four mean thicknesses, colour-coded: blue 0.087 mm, white 0.102, red 0.122, yellow 0.147. They are chosen to obtain a liner protrusion of 0.16 to 0.23 mm, “as close as possible to 0.23 mm”. Liner: 88 mm bore, 93.48 mm base spigot diameter. A310 2700 VA repair guide, folio B-9.
Rolled crankpins 52.267 to 52.286 mm, rolled main journals 70.043 to 70.062 mm, with a single −0.300 repair size (51.967 to 51.986 and 69.743 to 69.762). The crankshaft runs in 4 main bearings, aluminium-tin shells, 0.07 to 0.27 mm end float taken up by thrust washers of 2.30 / 2.40 / 2.45 / 2.50 mm. These figures tally with the 1976 SAE paper, which quoted 52.3 mm crankpins and 70 mm journals: this is indeed the crankshaft that went into production. A310 2700 VA repair guide, folio B-10.
The guide contradicts itself, and both passages are given here rather than one. The crankshaft specification table states “pre-tighten to 3 m.daN then 75° angular tightening” (folio B-10); the torque page refers to that same folio B-10 but writes “pre-tighten to 2 m.daN then 115° angular tightening” (folio B-12a) — exactly the cylinder-head method. Two other manuals in the Library give the same as folio B-10: the DeLorean workshop manual pre-tightens the main bearing cap nuts to 28 N·m then 75°, and the Volvo reconditioning booklet to 30-35 N·m then 73 to 77°. Neither covers the 112 engine, but two independent corroborations on the same engine family leave little room for doubt: folio B-12a copied the cylinder-head method. The connecting-rod caps, on the other hand, are given unambiguously at 4.5 m.daN, side clearance 0.20 to 0.38 mm. A310 2700 VA repair guide, folios B-10 and B-12a.
In m.daN: rocker covers 1 to 1.5 · intake manifold 1 to 1.5 · long-reach taper-seat spark plugs 1.7 to 2 · camshaft sprockets 7 to 8 · crankshaft pulley nut 17 (Loctite) · flywheel bolts 4.5 (Loctite) · timing cover 1 to 1.5 (lower bolts Loctite) · oil-pump sprocket 0.5 to 0.75 (Loctite) · oil pump 1 to 1.5 (Loctite) · chain tensioner blades 1 to 1.5 (Loctite) · TDC take-off plug 3.5 · sump drain plug 3.5 · coolant drain plugs on the cylinder block 3.5 to 4. A310 2700 VA repair guide, folio B-15.
Type 112.7.30, six cylinders in V, 88 mm bore × 73 mm stroke, 2664 cc, compression ratio 10.1:1 — the highest in the Library — 150 hp DIN at 6250 rpm and 20.8 m.daN at 3500, 15 French fiscal horsepower. Fed by two Solex carburettors: a 34 TBIA single barrel and a 35 CEEI twin barrel. Idle 800 rpm. Oil capacity 6.5 litres (0.25 of it for the filter). Firing order 1-6-3-5-2-4, like every PRV. Two figures the web data sheets never give: the dressed engine weighs about 152 kg, and engine plus manual gearbox about 225 kg. The engine carries two identification plates — one riveted to the crankcase, the other glued to the timing cover — giving the type, the RNUR identity and the build number. Alpine A310 2700 VA repair guide, engine section, folio B-5a.
No, and two dimensions prove it. New head height: 110.87 ± 0.15 mm on the A310, against 111.07 mm at Volvo and DeLorean — two tenths less, read off the plate. And chamber volume 53.8 ± 0.6 cc, for a 10.1:1 compression ratio on the Alpine, where the Volvos and the DeLorean run between 8.8 and 9.3:1. ⚠️ But these two figures are not enough to say the head is made for a more highly compressed engine: the 1975 Renault 30, at 8.65:1, gives exactly the same — 110.87 ± 0.15 mm and 53.8 ± 0.6 cc, with the same 0.6 cc rule between chambers. What separates the A310 from the R30 therefore lies elsewhere than in these two figures, and neither manual says where. The guide adds a requirement found nowhere else: “the difference in volume between two combustion chambers on the same head must not exceed 0.6 cc”. And the same prohibition as everywhere: maximum warp 0.05 mm, “no machining permitted”. Alpine A310 2700 VA repair guide, engine section, folio B-6a · Renault 30 M.R.167, folios B-3 and B-6.
Six hours of cooling at least — and the guide covers the case where you cannot wait: “NOTE: after only one hour of cooling, tighten the head bolts to 3.5 m.daN then carry out the angle tightening” instead of the usual 2 m.daN. A head still warm does not take torque the same way: you compensate at the pre-tightening stage. Two further points are worth knowing. First, before anything else you must slacken the inlet manifold bolts and those holding the timing cover to the heads, or the head is clamped. Second, the 1000 km re-torque is no longer required on new and exchange engines — “improvements on the production line allow it to be skipped” — but it remains compulsory after any head gasket replacement, between 500 and 1000 km. Alpine A310 2700 VA repair guide, engine section, folios B-6a and B-23.
Because it is not really one — and it must on no account be removed. The guide: “the engine is fitted with an oil pressure sender on the oil filter side (left bank) and an oil pressure switch on the right bank. That switch is not connected to the wiring harness. Its role is solely to close the leak hole in the oil gallery. Consequently, never replace it with a plug. Doing so would result in a drop in engine oil pressure”. We read it word for word off the plate, so surprising is the instruction: an electrical part with no wire, serving only as a blank, and which a plain plug will not replace. It is also where the test gauge is connected when measuring oil pressure. Alpine A310 2700 VA repair guide, engine section, folios B-19 and B-74b.
With the 310.21 pin, slid into the block's TDC take-off hole: rest it on the crankshaft counterweight, then “turn the crankshaft slowly in its normal direction until the pin drops into the notch and locks the crankshaft. In that position, cylinder no. 1's piston is at TDC”. It is word for word the method Volvo describes with an 8 mm drill: same engine, same notched counterweight. It is used to set the timing plate: in that position the “0” mark must fall opposite the pulley's slot; if not, move the plate. Two finishing touches the guide insists on: paint the plate's screws and washers “so that any later disturbance shows”, and torque the TDC take-off plug to 3.5 m.daN. Alpine A310 2700 VA repair guide, engine section, folio B-70.
In three moves, before the timing light even comes out. One: turn the crankshaft in its normal direction to bring cylinder no. 5's rockers on the rock — that is cylinder no. 1's firing TDC. Two: bring the pulley notch against the 10° mark on the plate. Three: new gasket under the base, then align mark (R) on the rotor with mark (P) on the distributor body, on the vacuum capsule side, and fit the distributor with the capsule perpendicular to the edge of the head. Finish by fitting the cap and connecting the leads “following the marks on the cap and on the heads”. Final timing is then done with a strobe. Note: it is the right camshaft that drives the distributor — the left one carries the fuel pump eccentric. Alpine A310 2700 VA repair guide, engine section, folios B-16 and B-70.
The left bank, and the Alpine guide explains why the question arises: “NOTE: despite the engine's installation, we consider, for reasons of standardisation, that cylinders 1-2-3 form the left bank or group A, and cylinders 4-5-6 the right”. In other words Renault fixed a convention valid for every PRV, whatever way the engine sits in the car — overhung at the rear on the A310 as on the DeLorean, in line at the front on a Volvo 260. That is why the DeLorean technical manual, which defines left and right standing behind the car, seems to contradict its own workshop manual. The physical landmark never lies: cylinder no. 1 is the one nearest the flywheel, and the rods are numbered “no. 1 at the flywheel end”. Alpine A310 2700 VA repair guide, engine section, folios B-16 and B-44b.
Yes, almost everywhere: “the tapped holes of every part making up the engine can be restored using thread inserts, except the M25×1.50 tapped hole for the oil gallery plug in the crankcase”. One exclusion only — and for the spark plugs, “special spark plug” inserts are required, not ordinary ones. The Volvo manual, on the same engine, publishes a longer exclusion list (oil filter thread, big-end bolts, adjusting screws, the manifold's conical threads), which gives the sensible rule: on an engine where almost every part is aluminium alloy with threads tapped straight into it, the insert is the standard repair — but never on a part whose failure endangers the engine. Alpine A310 2700 VA repair guide, engine section, folio B-16; Volvo workshop manual, section 2 (21), page 15.
6.5 litres — but only from the 1978 model year: “the sump capacity was raised to 6.5 l on 1978 model year 2700 VAs. The dipstick was modified accordingly”. On an earlier car the original dipstick (part no. 77 00 268 538) therefore shows marks that no longer match if you fill to the new capacity. The guide offers better than a warning: the dimensioned drawing to modify the old dipstick by grinding — new maximum at 6.5 l, new minimum at 6 l. It is exactly the sort of detail which, ignored, makes a perfectly healthy car look like it is using oil or running low. A reminder: 0.25 litre of that capacity goes into the filter. Alpine A310 2700 VA repair guide, engine section, folios B-5a and B-74b.
By getting the oil properly hot: “the pressures are valid only for an oil temperature of 80 °C in the sump”. The method: warm it up at 2000 rpm, and keep it at that speed for at least five minutes AFTER the cooling fan has cut in — that last condition is the one always skipped, and it changes everything. Stop, connect the gauge in place of the oil pressure switch, restart and read: 2 bar at 800 rpm, 4.4 bar at 4000 on a new engine. Two valuable qualifications: “a drop of 0.4 bar is acceptable depending on mileage” — a slightly low pressure is not a death sentence — and, if the readings are poor, “we advise you, before any mechanical work, to change the oil and repeat the check with fresh oil”. Alpine A310 2700 VA repair guide, engine section, folio B-74b.
In two stages, and it is unusual: “screw the filter on until the seal contacts its face. Tighten the filter a quarter of a turn with tool Mot. 445. Unscrew the filter, bring it back into contact and tighten it again by half to three quarters of a turn”. A first nip beds the seal down, you release, then tighten for good — insurance that the seal does not roll over. Two more instructions on the same folio: oil the new filter's seal with engine oil before fitting, and above all use only a filter with a built-in valve — a filter without a non-return valve lets the gallery drain when the engine stops, and it starts up dry. When rebuilding a complete engine, prime the oil pump by injecting oil with a can through the hole below the filter connector. Alpine A310 2700 VA repair guide, engine section, folios B-73a and B-74b.
Three, each pinned to a serial number, and all useful to anyone hunting parts. From no. 44 101: the exhaust's Paulstra link and mount are no longer fitted, “negligible role”. From no. 44 271 (plus seven individual cars, 44 240, 44 257, 44 258, 44 263, 44 266, 44 267 and 44 269): the new exhaust manifolds go from 41 to 43 mm in diameter, which compels the fitting of new primary silencers (left 60 00 059 935, right 60 00 059 936) and two sealing gaskets — so a new manifold cannot be married to an old silencer. From no. 46 354: the drain plug (A) is replaced by a coolant warning thermo-switch — which must be unplugged before draining. Alpine A310 2700 VA repair guide, engine section, folios B-36b, B-39b and B-54b.
With a chemical solvent and a wooden spatula, never a metal tool: “do not scrape the aluminium gasket faces”. The guide names the products: Magnus “Magstrip” to dissolve gasket remains — apply it, leave it ten minutes or so, lift it off with the spatula, gloves advised — and Supermagnusol 5 to clean faces that have had Rhodorsil CAF 33 sealer on them. But the real reason for the warning lies elsewhere, and it is repeated three times in the chapter: “avoid introducing foreign matter into the pressurised oil feed galleries to the rocker shaft. Failure to observe this may block the rockers' jets and cause rapid destruction of the cams and pads”. The holes concerned are plugged with rag during the work. Alpine A310 2700 VA repair guide, engine section, folios B-28, B-44b and B-58.
It derives from it very directly, and a cross-reading leaves little doubt. Same dimensions: liner protrusion 0.16 to 0.23 mm “as close to 0.23 as possible”, base seals blue 0.087 · white 0.102 · red 0.122 · yellow 0.147, 72 mm piston pin, rings 1.5 / 2 / 4 mm, thrust washers 2.30 · 2.40 · 2.45 · 2.50, rod nuts at 4.5 m.daN, mains pre-torqued to 3 m.daN then 75°. Same gestures: pin shrunk at 250 °C with a piece of solder as the gauge, rocker shaft turned round but never reversed, 5.35 and 8.2 mm spacers, piston no. 1 15 mm before TDC to fit the heads, 150° of crankshaft between left and right timing, right down to the wording on the tensioners: “ne pas aider son action” — “do not assist the tensioner”. Even the same worked example for shim selection (0.10 and 0.08 mm, hence a red tag). The DeLorean did not merely receive Renault's engine: it received its workshop documentation. Alpine A310 2700 VA repair guide, engine section, folios B-9, B-19, B-35, B-46, B-49 and B-65; DeLorean workshop manual, engine section.
At 80 °C, minimum pressure: 2 bar at 800 rpm and 4.4 bar at 4,000 rpm. ⚠️ This figure applies to the A310's 112 engine and to it alone: the Z engines have their own pressures, given in their own manual. A310 2700 VA repair guide, folio B-11a.
To plug a hole — and above all not to be replaced. The engine carries an oil pressure sender on the filter side (left bank) and, on the right bank, a switch that is not connected to the wiring harness. Its only role is to close the leak hole in the oil gallery. The manual warns: “never replace it with a plug. Doing so would cause the engine oil pressure to drop.” A310 2700 VA repair guide, folio B-19.
The tensioner is supplied locked by its pawl. On removal, disarm it by turning the pawl anticlockwise; on assembly, once in place, arm it by turning it clockwise — and the manual insists: do not help it along. In use, oil from the lubrication circuit pushes the piston, and the shoe can only move back by the 1.5 mm anti-return clearance before bearing on the rack. A310 2700 VA repair guide, folio B-19.
Idle at 800 ± 25 rpm. With an infrared CO-CO₂ analyser, set the volume screw (A) and the mixture screw (B) to obtain 2.5 to 3.5% CO. Without an analyser, aim for under 4.5% CO: find maximum speed on the mixture screw, come back to 800 rpm on the volume screw, then screw the mixture in to lose 60 rpm without upsetting smoothness. The manual ends with: “after adjustment, seal the mixture screw”. The two carburettors are a single-barrel Solex 34 TBIA and a twin-barrel Solex 35 CEEI. A310 2700 VA repair guide, folios B-11a and B-102b.
With the Mot. 647 wrench, engine cold: 0.10 mm intake, 0.25 mm exhaust. The guide gives two methods. Head by head — on the left (cylinders 1-2-3), with rockers A1-E1 rocking: set A3 and E2; A2-E2: set A1 and E3; A3-E3: set A2 and E1. On the right (4-5-6), A4-E4: set A6 and E5; A5-E5: set A4 and E6; A6-E6: set A5 and E4. In two crankshaft positions — piston 1 at firing TDC (rockers of no. 5 rocking, distributor mark facing the housing mark, pulley notch on the “O”): set A1, A2, A4 and E1, E3, E6; then one turn of the crankshaft, no. 1 at end-of-exhaust/start-of-intake TDC: set A3, A5, A6 and E2, E4, E5. A310 2700 VA repair guide, folio B-24.
The guide lists the production changes, each with its serial number: steel tubes in the backbone chassis (from no. 44,657), bleed screw under the water pump (44,369), filler neck on the left (44,657), radiator without turbulator, PC clips on all hoses (44,340) and thermo-switch ref. 60 00 056 901 (43,877). The circuit diagram changes too: the “2nd layout” dates from build no. 44,657. A310 2700 VA repair guide, folio B-85b.
Two ratings depending on the car's age: 0.8 bar valve up to serial number 46,649, 1.2 bar valve from 46,650. The test uses the MS 554 gauge, cold then hot: clamp the hose between filler neck and tank (Mot. 453 clamp) to take the valve out of circuit, raise the pressure in steps — 200, 400, 600, 800 g then 1 kg — checking for leaks at each. Then remove the clamp and raise to 1.1 bar (0.8 valve) or 1.5 bar (1.2 valve): the pressure must fall back and settle on the valve's rating, within 0.1 bar. ⚠️ Release the pressure before disconnecting the tool's cap. A310 2700 VA repair guide, folio B-85b.
Same figure for both — 38.5 mm ± 1 — but measured differently. On the 34 TBIA, with the float chamber top laid flat, air intake facing down, gasket (J) fitted and the needle ball compressed: measure between the chamber joint face and the top edge of the float body, and the needle clip faces stirrup towards the cold-start system. On the 35 CEEI, gasket removed, measure outside the cast sealing bead, and the clip faces the air intakes of each barrel. A310 2700 VA repair guide, folios B-97 and B-98.
On the twin-barrel 35 CEEI the guide is blunt: float, then first-barrel throttle (screw C) and second-barrel throttle (screw D) — the throttle edge must mask the progression slot without overrunning it — and “the carburettor has no other adjustments, mixture is set at the factory”. On the 34 TBIA, add the throttle angle (Mot. 522 and 522-02 tooling), the positive throttle opening checked with the MS. 532 gauge pins, the pneumatic choke pull-off and the accelerator pump end of travel. Two seals worth knowing: the throttle-angle screw is sealed from new with a black cap, to be replaced by a white cap after any intervention so that it shows; and the idle mixture screw is sealed after adjustment. A310 2700 VA repair guide, folios B-97, B-98 and B-102b.
The clutch shaft spigot bearing. As a spare part and on an exchange engine, it is not fitted to the crankshaft: you must fit it yourself on any engine destined for a manual gearbox. Also worth knowing before repairing a thread: the engine's tapped holes accept thread inserts, except the M25×1.50 hole of the oil gallery plug on the crankcase. A310 2700 VA repair guide, folio B-16.
Check with the engine at 80 °C, dwell angles and initial timing correct, idle at 800 rpm, reference taken on the “O” notch of the plate, offset timing light on cylinder no. 1. Initial advance: 10°. Main advance (initial + centrifugal), vacuum pipe disconnected and plugged: 1,050 rpm → 10 to 12° · 2,000 → 19 to 23° · 3,000 → 25 to 29° · 4,000 → 31 to 35° · 4,500 → 35 to 39°. Vacuum advance, read at 2,000 rpm (main advance 22°): 200 mm Hg → 0° · 300 → 7° (permitted curve 4 to 10°) · 400 → 14° (11 to 17°) · 450 and above → 16° (13 to 19°). A310 2700 VA repair guide, folio C-13.
Because its pulse generator is inductive, it can be made to fire by hand. The distributor holds a steel rotor with one tooth per cylinder — six on the Renault Alpine V6 GT, a magnetic core, an induction coil and a permanent magnet: as the teeth pass, the magnetic flux changes and induces an alternating voltage which the electronic unit turns into a spark. So a magnet moved by hand does the same job. Engine will not start: ignition on, cap off, pull the coil-to-distributor HT lead and earth it, hold the coil's HT lead as close as possible to the coil's terminal, then move a permanent magnet up and down opposite the distributor's induction coil — a spark must jump. No spark, and the fault is elsewhere in the ignition. Distributor suspected: unplug its connector, connect the two wires of a TDC pulse generator to the terminals on the electronic unit's side, and move the magnet in front of it. If a spark is now produced, the distributor is the faulty part and is replaced or repaired. Alpine M.R.273, folios C-4 to C-6.
To clean up the exhaust of a cold carburettored engine, and for a set time. During warm-up, a delay relay feeds a solenoid valve; once energised, it lets inlet manifold vacuum act both on the throttle opener — which holds a fast idle of 1,100 to 1,150 rpm — and on the distributor's vacuum capsule, which gives 15° of retard at the crankshaft. The relay's delay lasts between 13 min 40 s and 16 min 24 s. It starts when the starter is operated, provided the idle switch is closed (it is worked by the second-stage linkage) and the oil temperature contact is open — open between 15 and 35 °C. And as soon as the idle switch on the carburettor opens, the delay is interrupted. So a GTA that idles fast and feels flat for the first quarter of an hour on a mild morning is not necessarily out of tune: it may be doing exactly this. Alpine M.R.273, D501 update, folio B-41a.
Starting follows a rule of its own: “before operating the starter, press the accelerator fully once. During starting, do not touch the accelerator”, so that the idle switch keeps the system's circuit closed. Adjustments: accelerator floored, the throttle cable's compensator must be compressed by 3 mm — otherwise reset the cable outer's stop. The pedal switch is set with the engine cold, at 20 °C, using a test lamp: the lamp must light at the slightest press on the pedal; and its travel must still let the warm engine return cleanly to idle. Functional check, engine warm, capsules connected, speed stabilised for at least 2 minutes, after the cooling fans have cut out and with the air conditioning off: idle 800 +50/−0 rpm, CO 1% ± 0.5, timing 15° ± 1° at the crankshaft. Then the fast idle, with the vacuum hose run directly from the manifold to the capsules, bypassing the solenoid valve: 1,100 −0/+50 rpm, advance 0° ± 2, and no vacuum at the advance capsule. The “Swiss” cars are otherwise identical to the “Europa” ones; only the ignition control and the throttle opener control differ. Alpine M.R.273, D501 update, folios B-42a, B-44a and B-47a.
Engines Z6W A 700 and Z6W 702: centrifugal curve R 340, vacuum capsule J 18, ignition point 15° ± 1° at the crankshaft, vacuum capsule disconnected. Plugs Eyquem 803 4JS or 803 4JSP, electrode gap 0.65 ± 0.05 mm — a figure to keep to itself, since the same family runs 1.2 mm on the Safrane V6 and 0.9 mm on its four-cylinder. Firing order 1-6-3-5-2-4. And the note that prevents half the misreadings of an advance curve: the same graph serves both for checking on the car and on the bench, because 2° at the crankshaft = 1° at the distributor shaft, and two crankshaft revolutions = one distributor revolution. A curve read in distributor degrees against one read in crankshaft degrees is a curve read twice as flat. With no contact breaker there is no test lamp either: timing is set with a strobe lamp, or through the diagnostic socket on the flywheel side. Alpine M.R.273, folios C-2, C-9 and C-10.
One distributor, but two of everything else. The Ducellier 4498 A holds a shaft with three cams offset by 120°, two supply leads, two contact breakers and two condensers, plus its centrifugal and vacuum advance devices — and it feeds two ignition coils. Breaker A belongs to the circuit of coil A, which fires cylinders 1-2-3; breaker B to coil B, firing 4-5-6. One bank each, in a single body. Which is why each circuit is set separately: dwell and timing on bank A first, then the strobe's pickup is moved to cylinder 6's lead and the dwell meter's primary lead to coil B, with the engine running at 900 rpm, and bank B's timing is set with screw V before its dwell is checked. ⚠️ And one screw inside must be left alone: “the eccentric screw “E” must not be moved — it is set by the manufacturer”. It is the screw that fixes the relationship between the two breakers, so touching it means losing the setting between the two banks with nothing to restore it by. Renault 30 M.R.167, folios C-4 to C-7.
No — and the manual warns you in so many words: “for design reasons, the connection sequence marked on the distributor cap does not correspond to the firing order”. The leads are connected 1-4 ; 3-6 ; 2-5, in pairs, because a single cap serves two ignition circuits; the firing order is 1-6-3-5-2-4. Wire the cap by the firing order and the engine will not run; read the firing order off the cap and you will misdiagnose everything downstream. The settings that go with it, and they differ by bank: dwell 63 ± 3% on bank A and 63 ± 5% on bank B — the same nominal, a wider tolerance on B — which is 76° ± 3 and 76° ± 5 on a dwell meter reading in degrees. Ignition point 10° ± 1 at the crankshaft, or 26 ± 2.5 mm measured at the flywheel. Renault 30 M.R.167, folios C-2 and C-3.
By notches, shapes and colours — each bank has its own. Timing marks: with the manual gearbox, the flywheel carries one notch for bank A and two notches for bank B; with the automatic, the converter drive plate carries a triangular mark for bank A and a rounded mark for bank B. Coils: coil A is the one with a black rubber boot on its high-tension lead, coil B the one with a white boot — the dwell meter's primary lead goes on the coil of the bank being set, and the stroboscope's pickup on the lead of cylinder 1 for bank A, cylinder 6 for bank B. And the two banks are not set the same way. Bank A: distributor clamp loosened, dwell set with screw C at cranking speed, then timing 10° ± 1° at 900 rpm, and the distributor tightened. Bank B, engine running at 900 rpm: timing set to 10° ± 1° with screw V; then, vacuum hose reconnected, bank B's dwell is checked — it must still be within its tolerance, 76° ± 5°, once the timing is set. The diagnostic centre sequence says the same thing in its own words: bank B's timing is set “if necessary by altering the dwell angle”. Idle speed, 900 rpm, is set with the adjusting screw A (carburettor chapter). With the MS 660 meter, the principle is unchanged: its plug in the car's diagnostic socket, the inductive clamp on the lead of cylinder 1, then cylinder 6, at idle, one bank after the other, and the timing read on the meter's scale. Renault 30 M.R.167, folios C-5 to C-7 and C-15.
Removal, boxed in the manual: before taking it out, mark the distributor's position relative to the cylinder head and the rotor's position relative to the cylinder head; then undo the fixing nut and remove the clamp. Refitting: if in doubt about its orientation, line up the line mark R on the rotor with the mark P on the distributor body, on the vacuum capsule side; bring cylinder 1 to TDC, both valves closed; and fit the distributor so that the vacuum capsule is at a right angle to the cylinder head, 90° ± 5°. On the distributor test bench, the two circuits are again set separately. Bank A: supply lead on breaker A's lead, dwell of breaker A set to 76° ± 3° — the white zone of the degree disc — and the disc left in that position. Bank B: supply lead on breaker B's lead, then turn adjusting screw V until, seen in the direction of the arrow, the start of the dwell lies at 75°, and at 45° in the opposite direction; boxed: bank A's dwell setting must not be altered while doing this. Then turn the degree disc clockwise until its 0° mark coincides with the start of the dwell, and check: B must be within 76° ± 5°. The same Ducellier principle appears in the Alpine A310's guide, which calls it the “75°-45° distribution” and gives the same window, 71 to 81°; the Renault 30's page adds no correction rule. Renault 30 M.R.167, folios C-8 and C-9 · Alpine A310 2700 VA repair guide, folio C-6a.
At the end of the right-hand cylinder bank, on the flywheel side. With it and the recommended equipment, the manual lists what can be done: setting the ignition timing; setting the contact breaker of bank A — dwell and contact resistance; checking the advance curves, centrifugal and vacuum; and checking the coil's primary circuit. The socket has 12 pins, of which 6 are used: 1 pulse generator, red · 2 earth, yellow · 3 breaker A, black · 4 + coil, white · 5 pulse generator lead shielding (no colour given) · 6 pulse generator, grey. On the harness side, three leads: A to the breaker, B to the coil +, C the pulse generator. One boxed warning: only connect the matching plug to this socket. And a detail that follows from the table: only bank A's breaker is wired to the socket — bank B's is reached with a separate clip on coil B's breaker terminal when the diagnostic centre tests it. Renault 30 M.R.167, folios C-10 and C-15.
At 0.5 to 1 mm from the flywheel — that is the gap the manual gives for it to work properly. A new sensor sets itself: it has three lugs on the flywheel side; bring the three lugs into contact with the flywheel and tighten clamp screw 3. A used sensor whose lugs are worn: bring it into contact with the flywheel, mark its position, pull it back about 1 mm, and tighten the clamp screw. Removing socket and sensor: disconnect the battery; take the socket out of its holding plate — without removing the plate; disconnect the earth, breaker and coil + leads; loosen the sensor's clamp screw; and if the plate must come off too, remove its two bolts. Boxed: do not bend the sensor's holding plate. Removing the sensor alone: battery disconnected, socket out of its plate, loosen the clamp screw of the harness sleeve and remove the sleeve, then push the round connectors (1-4-5) out of the socket with a home-made tool the manual dimensions: a rod 100 mm long ending in a tube 20 mm long, Ø 5 mm outside, bored Ø 3.7 mm to a depth of 15 mm. Renault 30 M.R.167, folios C-11 and C-12.
In the same order as on a four-cylinder engine — but once per bank. The engine test can be run with the usual leads and sensors, without the diagnostic socket; using the socket requires an extra timing meter in the test cabinet (a Souriau or a Sun) and a special test harness: inductive clamp (1), high-tension pickup (2), plug for the car's socket (3), connector for bank B's breaker (4), plug to the centre's harness (5), and a clip for bank B's breaker (9). Dwell is read on the six-cylinder scale: 38° ± 3°, or ± 5°. Bank A — plug (3) in the car's socket, clamp on cylinder 1's lead, pickup on coil A's HT lead, vacuum hose: engine stopped, ignition on, primary circuit resistance or voltage drop, coil input voltage; at cranking speed, coil input voltage, ignition voltage at the coil output, dwell setting, and oil the felt in the distributor shaft and grease the cam; at idle, set the timing, centrifugal advance, vacuum advance, dwell variation, engine vacuum; at 1,500 rpm, breaker operation, plug firing voltage, secondary insulation, coil operation, condenser operation; at 1,500 rpm with a sharp throttle blip, firing voltage and plug condition; at 3,000 rpm, dwell variation, plug firing voltage, secondary circuit resistance, maximum coil voltage. Bank B — clamp on cylinder 6's lead, connector (4), clip (9) on coil B's breaker terminal, pickup on coil B's HT lead: the same stopped and cranking checks without the dwell setting or the felt and cam lubrication; at idle, timing (if necessary by altering the dwell), dwell variation, and CO test and idle setting; then the same 1,500 rpm checks — and no 3,000 rpm stage. Last, the cylinder comparison test at 1,500 rpm, two measurements per bank: bank B with the clamp on lead 6, then on lead 4; bank A with connector (4) pulled out of the harness, clamp on lead 1, then on lead 3. Renault 30 M.R.167, folios C-13 to C-16.
Alternator: disconnect the battery terminals and the alternator's leads; remove the tensioner bracket bolt, the V-belt and the mounting bolt, and catch the alternator. Refit in reverse order and tension the belt as described in the Engine chapter. One boxed warning, with its reason: never lever the V-belt off with a screwdriver — it damages the belt's fabric. Starter: disconnect the battery; remove the oil filter; raise the front left of the car and remove the left front wheel to reach the starter bolts; remove the three bolts and turn the starter slightly about its own axis; disconnect the starter cable; take the starter out, then the cover plate. On refitting, the cover plate goes onto the centring pin on the clutch housing first, then the rest in reverse order. Renault 30 M.R.167, folio C-17.
No, and the manual explains why in one sentence: “these plugs have a conical seat (a) instead of a sealing ring, and must therefore be tightened to a torque of 1.7 to 2 m.kg”, using plug spanner n° 79 10 245 598. The plug is a Champion BN 9 Y, gap 0.65 to 0.75 mm. The distinction matters because the family contains both kinds: the Safrane's V6 takes a gasketed plug tightened to 2.5 to 3 daN.m — around 50% more — while a taper-seat plug torqued to a gasketed figure will crush its seat into an aluminium head. The same manual makes the point on its four-cylinder cousin, where a taper-seat J7R plug goes to 1 to 2 daN.m against 2.5 to 3 for the gasketed V6. Read the seat before reaching for the torque wrench. Renault 30 M.R.167, folio C-2 · Safrane M.R.302, chapter 17.
Between 0.5 and 1 mm from the flywheel — and the manual gives two ways of getting there, depending on the sensor's condition. A new sensor sets itself: it carries three spacing pins, which are simply brought into contact with the flywheel before the screw is tightened; the pins then wear away and leave the gap. A used sensor whose pins are already worn has to be set by hand: bring it up against the flywheel, mark the position, back it off about 1 mm, and tighten. The sensor works with the diagnostic socket on the flywheel side of the engine, which allows the ignition point, the advance curves — centrifugal and vacuum — and the engine speed to be checked without dismantling anything. Alpine M.R.273, folio C-11.
At rest, it is shut — the air circuit is closed, the valve pushed back against the coil by its spring, the core held against the valve by a small spring. Ignition on and engine idling, the coil is fed, the magnetic field moves the core and the valve opens; the computer holds a cyclical opening pattern matching the air flow the idle needs. The subtlety is electrical: the valve has a permanent + 12 V supply and is controlled by earthing, in sequence. Total feed period about 6.1 ms, maximum sequential earth period 6 ms, which is 100% opening. ⚠️ And two instruments read it in opposite directions, which is where readings get misinterpreted. A pulse detector on track 2 of the valve connector (orange-green wire) measures the earth cut-off time: 6 ms means the valve is almost closed, 0.3 ms means it is fully open. The XR25's # 12 uses the opposite convention: 0% = closed, 100% = fully open. As an example at warm idle, the manual gives 3.5 ms on the pulse detector and 32% on the XR25. Fault finding: a faulty valve makes the engine stall as soon as the accelerator is released. Check the coil resistance — 9 to 30 Ω — and the presence of + after ignition on the feed wire, which is live, engine stopped, for about one second after the ignition is switched on. Safrane M.R.302, chapter 17.
Absolute pressure sensor: on the Z7X, on the right-hand side of the air filter, with a Ø 1.2 mm jet in its vacuum pipe (Ø 1.5 mm on the J7R-J7T, manifold side). Throttle potentiometer: on the throttle housing, and not adjustable — when replacing it, check the values under # 17. Hitachi idle valve: on the intermediate manifold. Knock sensors: two, at the bottom of the V, under the intake manifold. Oxygen sensor: car on a lift; remove the protective cover over its connector, disconnect the wiring, unscrew the sensor — without dropping it. Refit at 2.7 to 3.7 daN.m (against 2.7 to 3.4 on the Alpine A610 and the R25 V6 Turbo); check the wiring route and its clips — the wires must not touch any heat shield under the body; refit the upper shield hook. Its wires must be neither spliced nor soldered — broken wires mean a new sensor. And for an unstable or jerky idle, check with a voltmeter that the sensor heater gets 12 V. The sensor is an NGK, heated, fed + after ignition so it works sooner after starting: at 850 °C, 625 to 1,100 mV rich and 0 to 80 mV lean. Wiring checks: board MS 1048 in place of the computer's 35-way connector — always battery disconnected, ohmmeter only, never 12 V on the test points. Safrane M.R.302, chapters 12 and 17 · Alpine M.R.297, folio 17-21.
Champion BN 9 Y, electrode gap 0.55 to 0.65 mm. The guide adds a detail that matters on reassembly: they are gasketless, taper-seat plugs — the torque table gives them at 1.7 to 2 m.daN. On a taper seat in an aluminium head, it is the torque that seals, not a crushed washer. A310 2700 VA repair guide, folios C-2 and B-15.
Because the distributor does not distribute in the order the engine fires: “by the design of the distributor, the connection order shown on the cap does not correspond to the firing order”. The leads go on in the order 1-4; 3-6; 2-5, while the engine fires 1-6-3-5-2-4. The reason lies in this very unusual distributor's architecture: it carries a three-lobe cam at 120°, two supplies, two contact breakers and two condensers, but a single centrifugal advance and a single vacuum capsule. Breaker A controls coil A, feeding cylinders 1-2-3; breaker B controls coil B, for cylinders 4-5-6. Two coils, two breakers, one advance: Renault's mechanical answer to the uneven firing intervals of the 90° V6. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folio C-5a.
One first, the other relative to it — and if the second does not fall right, you go back to the first. On the bench, distributor driven at 300 rpm: set breaker A to 76° ± 3 of dwell with screw C, check that between 400 and 2500 rpm the angle does not vary by more than 3° and that there is no contact bounce, then that the three opening points are spread at 120° ± 2. Move on to group B: align the rotor's mark with the body's, on the capsule side, and set the 75°-45° distribution with screw V. Group B's dwell must then fall between 71 and 81°. If not, the rule is counter-intuitive: “above 81°: bring group A back to 73° and start again; below 71°: take group A to 79°”. And a prohibition in capitals: “DO NOT TOUCH THE ECCENTRIC'S SETTING (factory set)”. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folio C-6a.
By doubling everything — except the vacuum. The guide sets the rule: “1 distributor degree = 2 engine degrees; 1 distributor turn = 2 engine turns”, and for the vacuum curve, “the vacuum remaining the same”. The guide's own example beats any calculation: “bench reading at 2000 distributor rpm: read 12°. Strobe reading on the car at 2000 engine rpm: read 24° at the crankshaft, on top of the initial advance, that is 24° + 10° = 34°”. It is the classic distributor-testing error: comparing a bench curve with a strobe reading without converting, and wrongly concluding the advance is double or half what it should be. The A310's curves carry references worth knowing: R.300 and M.79 for the centrifugal, M.79 or D.66 for the vacuum. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folios C-4 and C-5a.
By working on two different springs, each responsible for half the curve. The guide gives the four cases, figure by figure: “the first part of the curve starts too early → tighten the fine-wire spring; too late → slacken the fine-wire spring. The second part starts too early → tighten the heavy-wire spring; too late → slacken the heavy-wire spring”. The fine spring governs the bottom of the curve, the heavy one the top: that is the essence of a two-stage centrifugal advance. For the vacuum curve, a single adjustment: the cockscomb — “if the curve starts too early, turn the cockscomb clockwise; too late, anticlockwise”. All of it on the bench, cap and rotor removed. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folios C-8 and C-9.
With the cap of a plug lead. The guide describes the method for pre-timing the distributor, and it needs nothing else: “remove cylinder no. 1's spark plug, block the plug well with the cap of the ignition lead, then turn the engine until the cap is ejected”. The cap only blows off on compression — so cylinder no. 1 really is coming up on compression and not on exhaust, which separates the two TDCs the crankshaft passes each cycle. All that remains is to “bring the pulley mark against the 10° graduation on the plate” to offer up the distributor. For exact TDC, though, the 310-21 pin in the TDC take-off hole is the authority. An equivalent workshop variant: bring cylinder no. 5's rockers on the rock. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folios C-6a and C-14.
To check everything about the ignition without dismantling anything. Sited on the right cylinder head, flywheel end, it allows, with a SOURIAU or SUN station fitted with the TDC sensor kit or with the MS 760 tool: checking the primary circuit, checking and setting the contacts, timing the ignition, verifying the centrifugal and vacuum advance curves and measuring engine speed. The socket has twelve cavities, six of them used: TDC sensor signal (red and white), sensor screening (grey with a blue sleeve), distributor earth (yellow), breaker (black with a red sleeve) and coil positive. Two connection instructions: wires 1 and 2 must go on GROUP A's coil-and-ballast assembly, “to avoid damaging the measuring equipment”, and the polarising keys (two at X, one at Y) must be respected when a new element is fitted. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folio C-17.
At 0.5 to 1 mm from the flywheel — and the guide gives two methods depending on whether the sensor is new. A new sensor carries three calibrated lugs: “bring the three lugs into contact with the flywheel and tighten the screw” — the lugs set the gap themselves, then wear away on the first turn. A reused sensor with worn lugs: put it in contact with the flywheel, “mark its position with a fine line on the body”, then back it off about 1 mm before tightening. Without that setting the diagnostic station never sees TDC and the whole ignition check collapses. The same sensor goes back after any powertrain removal — the engine section quotes the same 0.5 to 1 mm. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folio C-18; engine section, folio B-40a.
The guide gives three values for the same plug, and you need to know which to keep. The ignition section says “between 1.5 and 2 m.daN”, the engine section's torque table says “1.7 to 2 m.daN”, and the head assembly procedure says “tighten without fail to 1.75 m.daN”. All three overlap around 1.75 m.daN, which is therefore the target — the procedure's “without fail” settles it. The tool matters just as much: “use the special plug spanner 79 10 245 598 without an extension on the arm and tighten by hand” — or a spanner that accepts a torque wrench. An extension is tolerated “for loosening only”. And one precaution that applies to any conical-seat plug with no washer: “always make sure the thread and seat of both plug and cylinder head are clean” — it is the conical contact that seals. Alpine A310 2700 VA repair guide, electrical equipment and ignition section, folio C-2b; engine section, folios B-15 and B-32a.
13° ± 2 BTDC, at idle, engine at normal temperature — idle of 775 rpm ± 50 (automatic in park). Adjust by loosening the distributor hold-down nut and turning the body. One check comes first and is easily forgotten: with the vacuum hose disconnected at the distributor there must be NO vacuum at idle. If there is, the fault is in the idle speed control — limit switch adjustment, distributor vacuum cut-off solenoid, TVS thermal switch — and not in the ignition. DeLorean training manual, adjustments chapter, A1.
Not bank by bank: there is no provision to balance CO between the two cylinder banks, the engine idle screw being fully closed and therefore non-functional. The only adjustment is the total CO of both banks combined, on the air flow sensor screw. The figure: 1.0% + 0.3%, at 950 rpm — a speed obtained by opening the slotted idle screw on the inlet manifold, which is closed again afterwards. The measurement requires disconnecting the Lambda sensor under the car, at the connector above the left rear suspension (never directly at the sensor), bypassing the cooling fan temperature switch, and removing both exhaust pipe plugs at the manifolds to fit the sampling probes. The curb idle itself is non-adjustable: it is electronically controlled. DeLorean training manual, adjustments chapter, A2 and A3.
By a speed sensor reading the flywheel drive plate. The signal it sends the control unit is not regular: a longer pulse announces that a piston will be at top dead centre twelve teeth later. The unit combines this with the manifold absolute pressure (MAP) sensor to set the advance. So there is no centrifugal advance and no vacuum capsule to check as on the A310: the ignition is diagnosed with a voltmeter and a scope, not on a distributor bench. Two measuring precautions from the same chapter: on the MAP sensor as on the throttle position sensor, the probe tips go in through the back of the connector, without damaging the wires. 1990 Eagle Premier / Dodge Monaco service manual, folios 8D-2 to 8D-5 and 14-35 to 14-36.
Two — one per cylinder bank. A direct consequence of the V layout: a single ear cannot listen to six cylinders spread over two banks. Both are read on gate 13 of the XR25, which gives the total engine noise picked up by each. The Alpine A610's Z7X also has two, in the V between the banks, under the intake manifold — which has to come off to remove them; the catalysed R25 V6 Turbo's Z7U has only one, on the cylinder head under the fuel pressure regulator. Renault Safrane phase 1 M.R.302 workshop manual, chapter 17 · Alpine M.R.297, folio 17-3 · Technical note 1558, folio 17-1.
The computer flags the fault but does not say which: when a sensor weakens, the signal drops and right-hand bar graph no. 10 lights up. The manual's procedure to name it: XR25 connected, enter D03 # 13; engine warm, accelerate to 3,000 rpm with no load — the reading must be variable and not zero. Now disconnect one of the two sensors: if the value does not change, the sensor you just unplugged is the dead one; if it drops to zero, that one is good and it is the other that must be replaced. Safrane phase 1 M.R.302, chapter 17.
By the colour of the connector, and the manual is categorical about which goes where: the GREEN connector sensor must be mounted on the front bank — cylinders 1, 2 and 3 — and the BLUE connector one on the rear bank, cylinders 4, 5 and 6. The two connectors are found at the level of the suspended engine mountings, which is where you check them without dismantling anything. The sensors themselves are another matter: to reach them the inlet manifold has to come off, because they are screwed into the bottom of the V formed by the two banks. Which explains why swapping them by mistake is easy and awkward to undo — and why the colours exist at all. Checking is done on the XR25, bar graph 10 on the right hand side, for # 13 and # 15. Two sensors, because a single ear cannot listen to six cylinders spread over two banks. Safrane M.R.302, chapter 17.
On type B 544, engines Z7X 722 and Z7X 723: Eyquem RFC 58 LS3, gap 1.2 mm ± 0.05 — and the manual states « not adjustable »: you do not bend this plug's electrode, you replace the plug. It is a gasketed plug, tightened to 2.5 to 3 daN.m — not to be confused with the taper-seat plug of the J7R four-cylinder, tightened to 1 to 2 daN.m and gapped at 0.9 mm. The manual adds a warning: make sure the correct make and type are used, chosen for their heat range. ⚠️ And beware the trap: the Citroën XM V6 to 15-04 standards takes exactly the same reference — RFC 58 LS3 — but with a 1 ± 0.1 mm gap and a 1.5 m.daN torque. Same plug, two sets of figures: each manual holds for ITS car. Safrane phase 1 M.R.302, chapter 17 · Citroën Technical Note no. 4.
Because it is deliberate. The control circuit of the B29A's vacuum capsule is temperature-governed: below 55 °C (+4/−2), the advance is NOT corrected by vacuum; above 55 °C, and only for throttle openings beyond idle, vacuum correction comes into play. A capsule that does not pull on a cold engine is therefore not necessarily faulty — repeat the test with the engine warm before condemning it. M.R.249, NT 1205 E supplement, page 63.
A breakerless BOSCH ignition, identification number 0237402017, distributor timed at 10° at the flywheel. BOSCH HR 6 DC plugs, electrode gap 0.6 to 0.8 mm. The vehicle is the B29A: six cylinders, 2,849 cc, 91 mm bore and 73 mm stroke, compression ratio 8.8 ± 0.4, UN1 gearbox. M.R.249, NT 1205 E supplement, pages 4 and 63.
Two values, depending on temperature — and they are twenty degrees apart. Engine cold (water < 55 °C), at 2,500 rpm with no load: 23° ± 2. Engine warm (water > 55 °C), same speed: 43° ± 2. Back to idle: 10°. Alongside, the integrator voltage read between terminals 2 and 8 of the diagnostic socket tells the same story: it swings between 2 and 6 V as soon as the oxygen sensor is up to temperature, locks at about 6 V at idle (6.5 ± 0.5 V under regulation), stays between 4 and 8 V on a warm acceleration, and rises to 11 ± 2 V when cold or on pick-up. Checking the advance on a cold engine and concluding the distributor is out is therefore the easiest mistake to make on this car. M.R.249, NT 1205 E supplement, pages 53 and 59.
Eyquem FC 82 LS 3 plugs, gap not adjustable, tightened 2.5 to 3.5 m.daN. The advance no longer lives in a distributor: the curves are built into the injection computer, a distributor only shares out the high tension, and a power module (Z.L.M.) carries the knock sensor. The computer is a Siemens S 101 717 101, mounted in the passenger compartment, diagnostic code 108.3. The air and water temperature sensors are Bendix, NTC type — resistance falling as temperature rises, the opposite of the PTC sensors on the catalysed R25 V6 Turbo. The Bosch oxygen sensor is heated: at 850 °C, ≥ 625 mV on a rich mixture, 0 to 80 mV on a lean one. Catalytic converter C 22 under the floor, paper air filter every 20,000 km, Rochester canister. Alpine M.R.297, folio 12-2.
A distributor that no longer advances anything. The advance curves are stored in the injection-ignition computer, which sends a 5 V control signal to the ignition power module; the distributor only shares the high tension out, in the firing order 1-6-3-5-2-4. The module's connectors: three-way — A battery +, B earth, C free; two-way — A free, B control signal. Distributor check: remove its heat shield, then the distributor; inspect the electrodes and the carbon brush; measure the rotor's resistance with an ohmmeter — 0.8 to 1.3 kΩ; check that the O-ring on the insulating inner housing is there. Rotor tightened to 0.2 to 0.3 daN.m. Plugs: Eyquem FC 82 LS 3, gap not adjustable, 2.5 to 3.5 daN.m; to reach them, remove the intake manifold cover (3 screws) — tools Elé. 1086 and Elé. 721 help; on refitting, make sure the leads are fully home in the plug caps and run through their grommets. A second heat shield, the exhaust chapter notes, protects the distributor. Alpine M.R.297, folios 17-1, 17-2 and 19-7.
They are rare, so they matter. Do not skim a cylinder head's gasket face — four manuals, four manufacturers, the same sentence. Never use an air impact gun on the head bolts: the aluminium block's threads will not survive (Eagle). Do not lift a cylinder head straight up: the liners come out with it (Eagle). Never replace the right-bank oil switch with a plug: oil pressure would drop (Alpine A310). Do not run the engine without a thermostat, except for testing (Eagle). Do not use coolant additives claimed to improve cooling (Eagle). Never fill the cooling system with water alone (Volvo). Never use SE/CD oils (Volvo). Never exceed 600 kPa on the injector test rig (Volvo). Never insert a fuel tube into a quick-connect fitting without its retainer (Eagle). And two parts rules: the rocker arm's contact face against the camshaft must not be ground (Volvo), and a B28 piston whose pin has been driven out may not be reused.
Because it can be routed the wrong way — and the manual says so twice, in a boxed caution: “the belt MUST be routed correctly. Incorrect belt routing can cause the water pump to rotate in the opposite direction resulting in engine overheating”. On a serpentine belt that drives on both the flat and the ribbed side, the mistake does not show at a glance: it shows on the temperature gauge. The section's routing diagram is therefore part of the toolkit. Another precaution from the same chapter: coolant must not drip onto the belt or the pulleys — protect them with clean dry shop towels, and flush with water if it does. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-7 and 7-26.
The gaskets on the cylinder block drain plugs — those copper-coloured washers. The manual is categorical: they “MUST be replaced each time the drain plugs are removed”. On an aluminium block, this is the two-euro washer that saves a full redo. To be done at the same time, per the same chapter: refit the plugs with new gaskets before any filling, and route the thermostat housing bleed hose away from the accessory drive belt, the pulleys and the electric cooling fan. 1990 Eagle Premier / Dodge Monaco service manual, folio 7-13.
No — “do not operate an engine without a thermostat, except for servicing or testing”, says the Eagle manual. Two fitting details go with it, and they are easily lost: on the 3.0L the words “TO RAD” are stamped on top of the thermostat to show which way it goes, and both of the engine's thermostats have an air bleed valve. At Volvo the thermostat is chosen by its marking too — 82, 87 or 92 — which gives its opening temperature; fitting another changes the engine's thermal behaviour. 1990 Eagle Premier / Dodge Monaco service manual, folio 7-9; Volvo service manual, section 2, page 12.
Overheating, and the manual names three routes to it. First, a less than perfect engine: “the engine must be in perfect condition (above all the fuel system, the injection and the ignition) so that the converter does not have to work under abnormal conditions (at its limits)”. Second, carrying on driving: “the vehicle must without fail be stopped if misfires, fuel system faults, loss of power or other symptoms occur” — an overheating engine takes the converter with it. Third, and this one catches people out: prolonged cranking, or trying to tow-start the car. Under those conditions the engine is fed too rich a mixture for about a minute and fires abnormally — which is exactly what cooks a converter. One last warning, this one about fire: do not park the car, or leave the engine running, where flammable material could touch the hot exhaust; in certain weather it can ignite. The Alpine A610's manual repeats the same three causes and adds, before replacing a converter: check the car's fitness (fuel supply, ignition, mixture control by the oxygen sensor with the XR25 and a lead test, air filter), its performance on a road test, any noise from the converter, the exhaust's tightness, and the emissions warm at idle and 2,000-2,500 rpm — with particular attention to the exhaust around the converter and to spark plug leads properly seated. Technical note 1558, folio 19-7 · Alpine M.R.297, folio 19-11.
Two gestures, and the manual boxes them: “never pull off a high tension lead with the engine running” and “any high tension lead released for a functional check must have contact with earth”. It adds the consequence in one line: ignoring these measures can destroy the transistorised ignition. An HT lead left dangling has nowhere to discharge, and the energy goes back into the electronic module. The same chapter sets an order of work that saves modules: on misfires while driving, the electronic unit is replaced only after checking the plugs, the HT leads, the sealing caps, the distributor and the coil. And a point that catches out anyone used to contact-breaker ignitions: the primary voltage can neither be checked nor set with an oscilloscope — only the secondary oscillogram can be read, in the same way as on a conventional system. Alpine M.R.273, folios C-5 and C-6.
Because the heater matrix is part of the cooling system. The manual states it in three lines, the last of them in capitals: “there is no heater valve on the matrix. The coolant circulates permanently in the matrix, which contributes to cooling the engine. DO NOT CLAMP THE PIPES”. Clamping them to work on a hose, or fitting a shut-off tap “to stop the heating”, removes part of the cooling from a mid-engined car that already has its radiator at the far end of two long rigid pipes. The same page explains the bleeding that follows: unhook the expansion tank and hang it as high as possible, fill through it, open the two bleed screws — one on the thermostat housing, one on the front radiator — and close each as coolant comes out, level to MAXI, then run the engine at 1,500 rpm until the fans cut in. And a second prohibition: never open the bleed screws with the engine running. ⚠️ This is not an Alpine quirk: the Renault Safrane manual says it word for word — “there is no heater matrix valve. Circulation in the heater matrix is continuous, aiding engine cooling” — with the same ban on opening the bleed screws while the engine runs, and one instruction more: retighten the expansion bottle plug with the engine warm. It is a family rule, then, not a sports-car oddity. ⚠️ But not a rule of every era: the 1975 Renault 30, which has a heater tap and a conventional valved tank, does exactly the opposite — its manual says to run the engine for a few minutes after the thermostat opens, then open the bleed screws and close them as soon as coolant comes out in a steady jet free of bubbles. Each manual for ITS car: what is prescribed on an R30 is forbidden on a GTA. Alpine M.R.273, folio B-19 · Safrane M.R.302, chapter 19 · Renault 30 M.R.167, folio B-61.
Capacity 8.2 litres. Radiator with one row of tubes, 23 fins per inch. Electric fan of 14.6 inches with 5 blades. Thermostat: starts to open at 190 °F (88 °C), fully open at 214 °F (101 °C). The system normally works between 108 and 140 kPa (16 to 20 psi) — and the manual warns that exceeding this pressure may damage the radiator or the hoses. Draining and flushing recommended at 48,000 km or 30 months, whichever comes first. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-10 to 7-12 and 7-28.
RS 9YCX, gap 0.9 mm (0.035 inch), tightened to 15 N·m. The emission control information label under the bonnet repeats the gap and adds a line that amounts to an instruction: “NO ADJUSTMENTS NEEDED”. For comparison within the family: the DeLorean manual tightens plugs to 20 N·m, the A310 guide to 1.7-2 m.daN, and Volvo to 12 ± 2 N·m, without oiling them. 1990 Eagle Premier / Dodge Monaco service manual, folios 8D-18 and 25-2.
Cooling: water pump M8×1.25 27 N·m at the torque table, but 17.5 N·m in the fitting procedure — the same contradiction affects the thermostat cover (27 at the table, 12 in the procedure). Coolant temperature sensor M14×1.25 28 · electric fan to radiator M6 8.8 · radiator to condenser 4 (upper) and 5 (lower) · idler pulley to timing cover M10 40 · alternator, locking bolt 27 and pivot 50 · engine damper bracket 40. Manifolds and exhaust: intake manifold 15 N·m · exhaust manifold nuts 17.5 · hot air heat stove 19 · Y-pipe collar nuts at the manifolds 34 · converter to Y-pipe 34 · intermediate pipe to converter clamp 61 · muffler clamps 45 · oxygen sensor 30 · EGR valve mounting bolts 27 · EGR tube flange 19 and EGR tube line nut 40 · rear cradle bolts 125. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-7, 7-10, 7-28, 11-4 to 11-7 and 25-10.
Yes, and the Eagle manual supplies two examples in a single chapter. For the water pump bolts, the fitting procedure says “tighten to 17.5 N·m (13 ft-lbs)” while the torque table at the end of the chapter shows 27 N·m (20 ft-lbs) for that same M8×1.25 bolt. The same gap affects the thermostat cover: 12 N·m (9 ft-lbs) on assembly, 27 N·m in the table. Both figures really are printed; we read them off the plates. The separately published Chrysler engine overhaul book settles it: it too gives 17.5 N·m (13 ft-lbs) for the water pump. Faced with that kind of contradiction, the workshop rule is to take the value written at the point of assembly — it belongs to that part and that material — and to distrust the general table, which sorts fasteners by diameter: 27 N·m on an M8 going into aluminium is an M8-into-iron torque. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-7, 7-10 and 7-28.
1 bar (14.7 psi) at 790 rpm idle and 4 bars (60 psi) at 5500 rpm, on a gauge. The measuring condition matters as much as the figures: “check oil pressure only when the thermostat is open and the engine coolant temperature is at 89 °C (192 °F)” — a reading on a lukewarm engine means nothing, the oil is still too thick. Capacity: 5.7 litres (6 US quarts) with the filter. For context in the family, the DeLorean V6 asks for 2 bars at idle and the Volvo B28 at least 1 bar at 800 rpm: the American 3.0L sits in the same band, with a deliberately low idle. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, page 5.
Intake: opens 14° BTDC, closes 58° ABDC — a 252° duration. Exhaust: opens 56° BBDC, closes 12° ATDC — 248°. Overlap is 26°, a modest figure that explains this engine's flexibility and clean idle: it is an American saloon V6, not a sports engine. Compare it with the rest of the Library, where European PRVs on different camshafts show more generous overlap. A reminder: there is nothing to adjust on the valve side here, take-up is hydraulic, and timing is checked on the sprocket marks after 180° then 90° of rotation. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, page 6.
It splits production in two, and the list is long — it is the number to read before ordering any top-end part. Before no. 89616: liner protrusion 0.13 to 0.20 mm, head gasket 1.70 mm, head torque 20 N·m + 106°, re-tightening compulsory after running in. From no. 89616: protrusion 0.05 to 0.12 mm, gasket 1.45 mm, torque 40 N·m + 180°, no re-tightening, and a different rear crankshaft seal (interchangeable, but fitted with its own tool). The manual adds the essential: “the new and old style liners are not interchangeable” and “engines starting with engine number 89616 utilize a different gasket that is not interchangeable”. The number is on the tag on the right-hand side of the block, below the exhaust manifold: first six digits Z7X711, then the build sequence. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 5, 6, 21-24, 46 and 55.
Yes — on engines before no. 89616, and the manual puts it in capitals: “once the engine has been installed in the vehicle the cylinder head re-tightening procedure MUST be performed”. It goes like this: start and run for 15 minutes without load at 1800 to 2000 rpm, switch off, then let it cool for at least six hours; remove the valve covers and, in the tightening sequence, give each bolt a further 45° with the graduated disc; finally check with a torque wrench that every bolt holds at least 70 N·m. Two useful exceptions: this does not apply to engines from no. 89616 on, nor to the fitting of a complete replacement engine. It is the only procedure of its kind in the whole Library: the European angle-torqued PRVs ask for no such follow-up. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, page 62.
Because the liners would come with it: “do not lift/pry the cylinder head straight up, this will cause the cylinder liners to come up and out of the block”. So the manual's method is sideways: first drive the locating dowels down, below the gasket, with an old push rod or a long thin drift through the front and rear bolt holes on the exhaust side; leave one head bolt in the centre, tightened half a turn, so the head cannot slew; then hold a small block of wood against the head — first at the rear intake side, then at the front exhaust side — and strike it with a hammer until the head comes loose. And as soon as the head is off: liner clamps (tool 7315) in place, because “do not rotate the crankshaft without having the liner clamps installed”. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 18, 19 and 21.
No, and the reason is not clearance: “CAUTION: do not remove and install the cylinder head with the exhaust manifold attached to it. This will damage the tabs on the cylinder head gasket during installation”. This engine's head gasket carries tabs that run along the timing case, and a fitted manifold spoils the approach. Two more traps from the same chapter are worth stating: the head gaskets are not interchangeable left/right — “the left hand gasket has a larger cut out at the front” — and they go on dry, with no sealer, only a thin strip of RTV where the head gasket meets the timing case cover gasket. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 17, 22 and 55.
By the thickness of the liner seals, and the rule is finer than a simple range. Three requirements stack up: (1) the protrusion must fall within its model's tolerance — 0.13 to 0.20 mm before no. 89616, 0.05 to 0.12 mm after — and “it is preferred that the amount of protrusion be to the higher end of the tolerance”; (2) the difference between two adjacent liners must not exceed 0.04 mm; (3) protrusion must step down from no. 1 to no. 3 on the left bank, and from no. 4 to no. 6 on the right. In other words you are not after six identical figures but a slope. Measurement is by dial gauge on support blocks 6295/6296. This setting is the key to head gasket sealing on this engine — it is the first thing the diagnosis chart blames when a gasket blows. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 46 and 47.
They give its thickness, and thus set the protrusion. The seal is a steel washer between the liner flange and the block, and it comes in three thicknesses: RED 0.10 mm (0.004 in) · SILVER 0.12 mm (0.005 in) · BLUE 0.15 mm (0.006 in). Fit the one that brings the liner to the right height, and when reusing an original liner take “a new liner seal of the same thickness as the discarded seal” — because the protrusion was right. Two instructions go with it: NEVER reuse a liner seal, and “bend the sizing tabs up towards the top of the liner” on fitting. On new liners you start with a two-tabbed seal, then measure. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, page 46.
By the notches on top of the liner: one notch = 93.00 to 93.01 mm bore · two notches = 93.01 to 93.02 · three notches = 93.02 to 93.03. Three classes for three hundredths of a millimetre: that is how tight the matching is. It makes sense once you know the parts come in matched kits — liner, piston, pin and rings measured and paired in advance — which the manual says to mark with a common letter (A, B, C…) so two kits are never mixed. Two precautions on opening: the preservative coating comes off with acetone and “must never be scraped off”, and the ring end gap is already preset to the kit's liner — “there is no need to trim the ring ends”. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 8, 42, 43 and 48.
Hot, by shrink fit — there is no circlip. The small end is heated on a 1500 watt hot plate, and the temperature guide is neat: a piece of solder melting at 250 °C (480 °F) laid on the small end; when the solder liquefies, the rod is up to temperature. Wipe it, offer up the pin (which must turn freely in the piston — the interference fit is on the rod side), and push the mandrel home “as quickly as possible, to prevent the small end cooling and contracting”. Ten seconds' wait and it is done. Orientation is compulsory and differs between banks: on the left bank (1-2-3) the rod's large-end shoulder is opposite the arrow on the piston crown; on the right bank (4-5-6) it is on the same side. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 47, 48 and 50.
From the bottom, and it is mandatory: “the top of the cylinder liner is not chamfered. Do not install the piston from the top of the liner because damage to the piston rings and ring lands can occur. The piston MUST be installed from the bottom of the liner”. So piston and liner are assembled outside the block, with a ring compressor, before the assembly goes down into the crankcase. The rings: gaps 120° apart; the top compression ring is not tapered and goes either way up; the second is tapered and must have its face marked “TOP” upwards; the U-flex oil scraper goes either way. And to drop the assembly in, rubber hose insulators on the rod bolts, or they will nick the journal. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 48 and 49.
The marker is the squirt hole drilled in the rod's big end: “it faces the cylinder on the other bank directly across from it” — it lubricates the liner wall and the piston pin. Fitted backwards, it sprays nothing. In practice, on assembly: left bank (1-2-3), piston arrow towards the crankshaft pulley and rod shoulder towards the flywheel; right bank (4-5-6), arrow and shoulder towards the pulley. Three more rules: the rod caps are not interchangeable (mark them with the cylinder number on the outward face); loosen both nuts on a journal before removing either assembly; and tighten no rod nut until every liner is in place — then 47.5 N·m, with side clearance of 0.20 to 0.38 mm checked on feeler gauges. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 41, 49 and 50.
With thrust bearings available in four thicknesses: 2.30-2.35 · 2.40-2.45 · 2.45-2.50 · 2.50-2.55 mm. Aim for 0.07 to 0.27 mm, measured with a magnetic-base dial indicator on the bearing clamp, crankshaft pushed towards the flywheel (zero) then towards the pulley. Outside the range, change thickness — it is an adjustment, not a tolerance to accept. Two fitting details: the thrust bearings' oil grooves face outwards, towards the crankshaft thrust flanges, and the upper halves have a tab that sits in a notch in the block. For the rest: main and rod bearings come in one size only (70.06 and 59.97 mm); the upper main shell is grooved, the lower plain; and the caps are numbered 1 to 4 from the flywheel end, tabs pointing forward. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 41, 50 and 51.
Because it carries the joint to the gearbox: “when installing the lower casing, alignment plate tool no. 6140 MUST be used. Use of the alignment plate will ensure correct positioning of the lower casing and will avoid distortion to the convertor housing of the transmission”. On this bedplate V6, the rear face of the lower casing and that of the block must land in exactly the same plane, or the bellhousing no longer fits without strain. The sequence: a bead of RTV on the block face, casing fitted, every fastener started but loose, plate 6140 bolted into the rear seal housing holes, casing pulled back against the plate, then tightening in sequence to 30 N·m followed by 75° on the angular wrench. Lower casing bolts 17.5 N·m, rear seal housing 12 N·m. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 51 and 52.
No. The specification sheet says so in as many words, in brackets under the flatness line: “NOT RESURFACEABLE”. Maximum warpage allowed is 0.051 mm; beyond that, the head is replaced. Its nominal height is 110.83 mm and the combustion chamber volume 50.6 cc. It is the same rule as everywhere else in the Library — the PRV, with wet liners whose protrusion governs sealing, does not tolerate a skimmed head: you would move the gasket's clamping relationship on liners you never touched. Volvo, Alpine and the DeLorean forbid it too. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 6 and 7.
By counting the grooves machined on the outside of the guide you removed: no grooves = standard guide, outside diameter 13.0 mm (0.512 in); two grooves = repair guide, 0.526 in. And the instruction that goes with it: “do not install the same size guide as the one that was removed” — always go up a size, into a bore machined for it. Fitting is with 0.1 mm interference, the bore angle being 16.5°. A curiosity of reading: the metric value of that repair guide is printed 13.25 mm on one page and 13.35 mm on another — the inch figure, 0.526 in, settles it at 13.36 mm. It is the third faulty conversion we have found in the Library's American manuals: on these documents, the inch value is the one to trust. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 6 and 36.
Seats — top angle 8°, seat angle 45°, throat angle 60°; seat width 1.3 to 1.7 mm intake and 2.0 to 2.4 mm exhaust. Valves — face angle 45°, face width 1.45 to 2.21 mm (intake) and 1.6 to 2.64 mm (exhaust), minimum margin 1.5 mm and 1.7 mm; head 45.3 mm intake, 38.5 mm exhaust; stem 8 mm; length 112.45 and 111.45 mm. Springs — free length 48.5 mm, 337 N at 40 mm valve closed, 691 N at 31 mm valve open. Two workshop details: deburr the keeper groove at the top of the stem before withdrawing the valve, or you will score the guide; and the stem seals go in with two distinct tools — the 6187, silver, stamped INTAKE, and the 6200, gold, stamped EXHAUST. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 7, 8, 36 and 37.
With a drill bit, the thriftiest trick in the book. Pull on the top of the chain: a gap opens at the bottom, between the chain and the root between two sprocket teeth. That gap must not exceed 1.7 mm — and to gauge it you offer up the solid end of a number 51 drill bit, which is exactly 1.7 mm across: if it fits, the chain is finished. The manual also gives the tensioner equivalent: 1.7 mm of gap = 22 mm of tensioner plunger travel. The replacement rule is collective: “if either side has excessive wear, replace the timing chains, sprockets, guide shoes and tensioners for BOTH sides”. On a twin-chain V6, renewing one side alone means running two timing drives of different ages. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 25 and 60.
By squirting oil through the hole below the oil filter connector before closing it up — the pump sits inside the block, at the front, and nothing would prime it by itself after a full rebuild. The manual follows with an instruction too often forgotten: fill the new oil filter with clean oil before screwing it on. Pump details: the relief valve goes in open end towards the spring; never strike the cylindrical part that contains it; the cover torques to 12 N·m; and the pump sprocket bolts get Loctite 262 and 6 N·m — the pump chain goes on after the timing chains. And if the pump bores in the block are scored, it is not the pump you replace: “the cylinder block and pump must be replaced”. 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 42, 59 and 63.
No, and the Library holds both: the car's 1990 service manual and the 1989 engine overhaul book. Three gaps show up on a cross-reading. Spark plugs: 15 N·m in the service manual, 22 N·m in the overhaul book — in an aluminium head, and given the family (Volvo 12 ± 2 N·m, DeLorean 20, Alpine 17-20), the lower figure is the wiser one. Distributor cap screws: 4 N·m in the service manual, 9 N·m in the overhaul book — on a plastic cap, 9 N·m would crack it; take 4. Intake manifold: 15 N·m against 12.5. On the other hand the two books agree where you might have feared otherwise: exhaust manifold nuts 17.5-18 N·m, water pump 17.5, camshaft sprocket 80, crankshaft pulley nut 180. Reading rule: when two documents disagree, the one closest to the part and the more recent wins, and any lone figure in a general table is to be distrusted. 1990 Eagle Premier / Dodge Monaco service manual, folios 8D-18 and 9-44; 3.0L V6 engine overhaul book — Eagle Premier / Dodge Monaco, Chrysler Motors 1989, pages 22, 66 and 68.
Through the bleed valve on the thermostat housing, in two stages. Fit it with a hose of 6.35 mm inside diameter and 1219 mm long, routed away from the belt, the pulleys and the electric fan, the other end in a container. With the valve open, fill the pressure bottle slowly until a steady stream flows from the hose; close it, top up to the full mark — the top of the post inside the bottle — and fit the cap. Then start up, wait until the upper radiator hose is warm to the touch, switch off, reconnect the hose and open the valve again until the stream is steady. The full mark is the correct level for a cold engine; hot, it normally sits above it. This bleed is compulsory after removing any component of the system. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-12 and 7-13.
There is one per bank, and they hide: “remove the drain plug located behind and below each exhaust manifold” — hence the instruction to let the engine cool before reaching in. The detail that matters on reassembly: “the gaskets (copper coloured washer) on the V-6 cylinder block drain plugs MUST be replaced each time the drain plugs are removed”. A crushed copper washer does not spring back; reused, it weeps — and on a wet-liner engine, weeping at the block is always read the wrong way. The manual's safety reminder, in capitals: never remove those plugs, or the bottle cap, or loosen the radiator draincock, with the system hot and under pressure. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-11 and 7-13.
44 percent, year-round and in every climate — and the reason is not frost: “if the percentage is lower, engine parts may be eroded by cavitation”. On this all-aluminium wet-liner V6, antifreeze is not a winter product but a permanent workshop one. The manual's other landmarks: 50/50 recommended, protection down to -37 °C; 68 percent = maximum protection, -67.7 °C, beyond which the freezing point rises again; 100 percent glycol freezes at -22 °C and its corrosion inhibitors, which need water to dissolve, then form insulating deposits that drive the temperature up. The other side of this rule — too much antifreeze makes an engine run hot — is covered in the question on excessive concentration. 1990 Eagle Premier / Dodge Monaco service manual, folio 7-10.
Because a serpentine belt soaked in coolant slips — and a slipping belt drives the water pump badly, so it overheats the very engine you came to fix. The instruction returns with every procedure in the chapter, until it becomes a reflex: “when servicing the coolant system, it is essential that coolant does not drip onto the accessory drive belt and/or pulleys. Protect the belt with clean, dry shop towels before servicing. If coolant contacts belt or pulleys, flush them with clean water”. It is also why the bleed hose must be routed away from the belt, the pulleys and the electric fan. A cousin of the belt-routing rule, which is likewise paid for in overheating. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-5, 7-9, 7-13 and 7-16.
By the direction of the cracks, and it is counter-intuitive. “Small cracks that run across the ribbed surface of the belt from rib to rib are considered normal and not a reason to replace the belt. However, cracks running ALONG a rib (not across) are not normal. Any belt with cracks running along a rib must be replaced”. Also fatal: a rib torn from the belt body, a belt glazed and hardened by heat and slippage, a cracked tension sheeting. Tension with gauge 7198, in the middle of the span: 800-900 N for a new belt, 623-712 N for a used one — and a new belt is re-tensioned after 12 070 km. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-23 to 7-27.
Not necessarily, and the manual says so in its symptom chart: the fan only cuts in above 87 °C (the switch closes) and stops below 76 °C; in ordinary use and cool weather it may never run. A second, temperature-independent command: “the fan will run when the air conditioning compressor is engaged regardless of coolant temperature” — which is the quickest test. To force it, bridge terminals A and B of the coolant temperature switch with the ignition on: the fan should run; if it does, replace the switch, if not work down through the relay terminal by terminal. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-2, 7-18 and 7-20.
Because pressurisation happens at the expansion bottle, and it alone carries a cap: “the radiator does not have a pressure cap. The cap on the coolant pressure bottle is the only cap used in the system”. Coolant flows through that bottle at all times, cold engine or hot — so it is not a catch tank, it is a component of the circuit. Useful figures: the cap's valve releases between 110 and 124 kPa (16 to 18 psi) and that is how trapped air is purged; on the bench, pressurise the cap to 124 kPa and it must stabilise within ± 6.9 kPa (1 psi), or it is scrap. White deposits around the cap betray a leak. The system itself works between 108 and 140 kPa; beyond that, radiator and hoses suffer. 1990 Eagle Premier / Dodge Monaco service manual, folios 7-1, 7-11, 7-14 and 7-15.
Three methods, from simplest to surest. The ultraviolet lamp: every one of these cars left the factory with a tracer additive in the system; under black light a leak glows bright green (if the original coolant has been drained, add one ounce of additive). The pressure tester: adaptor on the bottle, engine warmed then stopped, pump up to 108-140 kPa (16-20 psi); the pressure must hold, otherwise there is a leak. And the internal leak, the one you cannot see: pull the oil pan plug and drain a little oil — “coolant, being heavier, will drain first” — or run the engine to churn the oil and look for water globules on the dipstick, the automatic transmission dipstick included. A block leakage tester for combustion gases is the last resort. 1990 Eagle Premier / Dodge Monaco service manual, folio 7-14.
It has a cap and a rotor, but it is no longer a distributor in the old sense: it only distributes high tension. No advance mechanism inside — no bob weights, no vacuum capsule — and “ignition timing (advance/retard) is controlled by the ECU and is not adjustable”. The high tension comes from an ignition control module (ICM) mounted on the coil, which the ECU triggers with a 5 volt square wave; the module charges the primary, opens it at saturation, and the secondary does the rest. The cap/rotor/dust shield assembly sits at the front of the left cylinder head, driven by the left camshaft. The workshop consequence: on this car you do not set the timing with a lamp — you diagnose sensors. 1990 Eagle Premier / Dodge Monaco service manual, folios 8D-1, 8D-2 and 8D-9.
With an ohmmeter, and nothing else: terminals A and B of the connector must read 200 ± 75 ohms with a hot engine; outside that, replace it — the sensor is not adjustable. It sits on the left side of the converter housing, behind the rear face of the engine, and torques to 8 N·m. What it reads is worth knowing: the drive plate carries three notches 120° apart with 20 small teeth between each, and every notch sits twelve teeth BEFORE the matching piston's top dead centre. As a notch passes, the gap between pulses lengthens: that relative silence tells the ECU a TDC is coming twelve pulses later. The other inputs to check alongside it: coolant temperature sensor (under 1000 ohms hot, 3400 at 20 °C) and manifold absolute pressure sensor (4-5 V with ignition on, 1.5-2.1 V at hot idle). 1990 Eagle Premier / Dodge Monaco service manual, folios 8D-3 to 8D-8.
With no flat gasket: by O-rings housed in the cylinder heads, one per port. The procedure is explicit both ways — on removal, “remove and replace the O-rings in the cylinder heads”; on fitting, “install new O-rings in the cylinder head. The original O-rings must not be reused”, then the manifold is torqued to 15 N·m. That is a clear difference from the European PRVs, whose inlet sits on a paper or metal-faced gasket. Another feature of the chapter: removing the manifold starts by taking off the fuel filler cap to relieve tank pressure, then by tagging every injector connector with its number before unplugging the harness — a harness refitted wrongly runs the engine on a false injection sequence. 1990 Eagle Premier / Dodge Monaco service manual, folios 11-8 and 11-9.
They are not symmetrical and the manual flags it in italics: “exhaust manifold gaskets have a ring on one side. Install the gaskets with the ring towards the cylinder head and the tabs towards the oil pan”. Fitted the wrong way round, the gasket does not bear where it should. The nuts torque to 17.5 N·m on both sides. Two removal traps peculiar to this car: on the right, the dipstick tube is held by a manifold nut — twist it gently to break the seal, pull it up, and on reassembly put Loctite 290 on its stop; on the left, it is the starter wires and the starter heat shield that pass under the lower nuts. 1990 Eagle Premier / Dodge Monaco service manual, folios 11-3 and 11-4.
Three prohibitions, all tied to one cause: unburnt fuel finishing its combustion inside the converter. One, never short out a cylinder: “do not remove spark plug wires from plugs or by any other means short out cylinders” — the old way of finding a dead cylinder kills the converter. Two, no fast idle beyond five minutes: “this may result in excessive temperatures in the exhaust system and on the floor pan”. Three, unleaded petrol only, or the catalyst core is poisoned. And the principle that links them: “excessive heat can result in bulging or other distortion, but excessive heat will not be the fault of the converter” — fuel, ignition or air injection must be put right at the same time as it is replaced, or the new one will melt like the old. The heat shields are not decoration: they protect the car and its surroundings. 1990 Eagle Premier / Dodge Monaco service manual, folio 11-1.
No — and that is a design difference, not a simplification. The 3.0L has a CCV system: “the CCV system performs the same function as a conventional PCV system, but does not use a vacuum controlled valve”. Instead, an oil separator is joined on one side to the air cleaner (fresh air) and on the other to the intake manifold through a nipple containing a 2.2 mm metered orifice: that hole, and only that hole, meters the crankcase vapours drawn back in. Nothing to rattle-test, nothing to replace at intervals — but block that 2.2 mm orifice with sludge and crankcase pressure has nowhere to go. Compare with the Library: the European PRVs do have a valved breather. 1990 Eagle Premier / Dodge Monaco service manual, folios 25-4 and 25-5.
The opposite of what you would expect: “if the electrical connector to the EGR solenoid is disconnected, the EGR valve will operate at all times resulting in poor engine performance and reduced driveability during certain operating conditions”. The logic is indeed inverted — vacuum only reaches the transducer when the solenoid is NOT energised; so the ECU is what forbids EGR when it must (cold engine, full load), not the reverse. An engine that hunts cold or feels breathless may have nothing worse than an unplugged connector. The field test follows the same logic: at the source, 15 inches of vacuum minimum; at the solenoid outlet, zero at hot idle; unplug the connector and vacuum must appear. 1990 Eagle Premier / Dodge Monaco service manual, folios 25-8 and 25-9.
Because the tank stays under pressure: the cap carries a two-way relief valve that only opens at 10 kPa (1.5 psi) of pressure or 6 kPa (1.8 in. Hg) of vacuum — below those thresholds it is closed to atmosphere. Hence the warning in capitals: “THE FUEL FILLER CAP MUST BE REMOVED TO RELIEVE FUEL TANK PRESSURE PRIOR TO DISCONNECTING ANY FUEL SYSTEM COMPONENT”. The evaporative system that goes with it is worth knowing: two rollover valves on the tank, normally open, which close with the car on its roof to stop raw fuel escaping through the vent hoses; and a charcoal canister purged not by a solenoid but by a venturi in the air cleaner housing — the incoming air stream creates the low pressure that empties it. 1990 Eagle Premier / Dodge Monaco service manual, folios 25-3 and 25-4.
To let the engine breathe warm while it heats up, for mixture and for emissions. The TAC system consists of a heat stove wrapped around the exhaust manifold, a heated air tube, a temperature sensor in the air cleaner cover, and a vacuum-motor air valve that blends hot and ambient air. The check takes four moves: engine stopped, the valve must be fully open to ambient air; on start-up below about 21 °C, it must be fully closed to ambient air; on a snap of throttle it briefly moves back towards cold air before closing again; hot engine, it must be fully open to ambient above 21 °C. If the valve does not move, connect direct manifold vacuum: if it then closes, the temperature sensor is at fault; if not, the vacuum motor. 1990 Eagle Premier / Dodge Monaco service manual, folios 25-6 and 25-7.
193 to 207 kPa (28 to 30 psi), engine running — about 2 bar, a long way from a K-Jetronic's 5 or so. And the manual warns: “the fuel pressure regulator is non-adjustable”. The diagnosis has two branches. Pressure too low: if fuel returns to the tank through the return tube, it is the regulator; if it does not, look at the pump, a clogged filter or a restriction between regulator and pump. Pressure too high: a leaking regulator vacuum hose, or a kinked return tube; failing that, replace the regulator. On reassembly the tube ends must be lightly lubricated with 30 weight engine oil. The supply tube is black, the return tube grey. ⚠️ One reading trap: the opening page of that same chapter announces '248-255 kPa (36-37 psi)'. Two passages out of three — the test procedure and the regulator description — give 193-207 kPa: that is this engine's own figure, read with adaptor 6175, and the only one to keep. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-3, 14-4 and 14-24.
No — it is simultaneous double fire, and the manual takes the trouble to explain: “all injectors fire simultaneously once every engine revolution, delivering half of the fuel needed for combustion. Since two engine revolutions are required to complete one engine cycle, the injectors fire twice every cycle”. One injector per cylinder, each spraying into the inlet port just above its valve — but no individual phasing. The ECU only varies the opening time (pulse width), the earth for all six injectors being switched together. That is the surprise: the engine does have a crankshaft position sensor, but it uses it for ignition and engine speed, not to inject cylinder by cylinder. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-17 and 14-22.
The documents say no — despite one stray sentence to the contrary. The injection chapter describes the warm-up mode thus: “if an engine knock is detected by the knock sensor, the ECU will retard ignition timing until the knock is eliminated”. But that sensor appears nowhere else: not in the ECU's two input lists (fourteen inputs, listed twice), not in the full pin-out of the ECU's four connectors A, B, C and D, not in the twenty-nine points of the visual inspection, nor in the diagnostic procedures. That sentence is boilerplate copied from another engine in the group — the kind of accident these American manuals are prone to. A family reminder: it is the European Z7W with Renix injection that carries a knock sensor; the K-Jetronic Z7V does not. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-17, 14-18, 14-26 and 14-33.
A great deal, in one to three seconds, and it is useful for diagnosis. It runs the fuel pump for 1 to 3 seconds to pressurise the system, then stops it; it energises the B+ latch relay for the same time; it stores a barometric pressure value read from the MAP sensor, for use at start-up; it opens the idle speed regulator; it powers the oxygen sensor's heating element; it blocks EGR by energising its solenoid; finally it feeds the injectors without earthing them, so without opening them. The practical upshot: “pump buzz for two seconds then silence” is normal on a healthy Premier — a pump running continuously with the ignition on would signal a fault. 1990 Eagle Premier / Dodge Monaco service manual, folio 14-25.
Floor the accelerator and crank: the ECU is programmed for it. “If a wide open throttle condition occurs during this mode, the ECU assumes that a flooding condition exists and will open all circuits to the injectors, preventing fuel spray to the cylinders. As long as this WOT condition exists, the injectors will not be energised”. So crank with the pedal flat until the cylinders clear. It is the electronic equivalent of the old carburettor trick — except that here the engine gets nothing at all, not even a trickle. The ECU recognises the condition through the throttle position sensor, so that sensor had better be correctly set. 1990 Eagle Premier / Dodge Monaco service manual, folio 14-26.
Yes, above a precise threshold: “if the ECU receives a closed throttle signal from the TPS while engine speed is over 1200 rpm, the ECU will determine that the engine is in hard deceleration and in response stop fuel injection and suspend EGR operation. It continues injection once the closed throttle condition no longer exists or when engine speed is below 1200 rpm”. On a gradual deceleration there is no cut-off: the ECU simply trims the pulse width. This detail explains two sensations at the wheel: the slight step as injection resumes around 1200 rpm, and zero consumption coasting downhill. Note that deceleration is an open loop mode: the oxygen sensor is ignored. 1990 Eagle Premier / Dodge Monaco service manual, folio 14-27.
In two modes out of eight only, and on one condition: idle and cruise, with the engine at operating temperature. There the ECU listens to the oxygen sensor and trims pulse width to hold “the ideal air-fuel ratio of 14.7 parts air to 1 part fuel”. The other six modes run open loop, computed from the map without listening to the sensor: ignition on, cranking, warm-up, deceleration, wide open throttle, ignition off. A diagnostic consequence: a dead oxygen sensor shows up neither on starting nor at full throttle — it shows at hot idle and on a cruise, exactly where the engine should be at its cleanest. The sensor's built-in heater exists precisely to enter closed loop sooner and stay there through long idling. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-24 to 14-27.
In four steps, from simplest to most dismantled. One, check the fuel pressure first (193-207 kPa): no point hunting an injector if the rail is not pressurised. Two, engine running, unplug the connectors one at a time while watching a tachometer: “an injector that is not operating will not cause the engine rpm to change when its electrical connector is disconnected”. Three, an ohmmeter across the suspect injector's terminals: about 2.4 ohms at 20 °C; outside that, replace it. Four, if resistance is right, a 12 volt test lamp on the harness side must flash while cranking; if it does not, the fault is in the supply or the control. As a last resort, remove the injector, check its inlet for blockage, and feed it 12 volts while touching the earth: it must click each time. 1990 Eagle Premier / Dodge Monaco service manual, folio 14-38.
Not to a voltage but to a ratio — which is what makes it immune to battery variation. Measure the input voltage between terminals B and C of the connector (about 5 V), then the output voltage between B and A, without unplugging (back-probe the connector). Divide: “the resulting output ratio should be .075 to .085” — 0.4 V out for 5 V in gives 0.08, which is right. Adjustment is by pivoting the sensor: rear screw for fine, front screw for coarse. Two fitting rules: “if the throttle position sensor is removed or the mounting screws are loosened, the sensor setting MUST be readjusted”, and a new throttle body arrives with its sensor already set. On assembly the sensor's lever goes on top of the throttle lever. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-40, 14-41 and 14-49.
By an idle speed regulator that bypasses the throttle: a permanent magnet motor drives a vane valve metering air taken from the air cleaner bonnet and returned into the adapter below the throttle plate. The B+ latch relay feeds it, the ECU switches its earth to open or close. So there is no idle screw to turn: idle speed is a target, not an adjustment. The ECU raises it when the gearbox goes into a drive range (neutral safety switch) and 0.5 second before the air conditioning compressor engages — thanks to a “predict” signal from the A/C module. To check: connect exerciser 7088 with adapter 7195; extending and retracting the valve must change engine speed, otherwise remove the regulator and watch the valve move in its ports. On fitting, the arrow cast into the body points towards the throttle body adapter. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-22, 14-23, 14-36 and 14-41.
No. It is made of two rails — one for injectors 1-2-3, the other for 4-5-6 — joined by a non-replaceable reinforced hose pressed onto nipples; the pressure regulator connects to the second rail through a hose of the same type. The manual is blunt: “the fuel rail and hoses are not repairable. They MUST be replaced as an assembly”. Only the pressure regulator comes off separately. On removal, two precautions: tag every injector connector with its number, and lubricate the injector O-rings with a drop of clean engine oil before pushing them back into the manifold. And the warning that covers the whole system: “the MPI fuel system pressure is not bled off when the fuel pump stops operating” — there will be fuel under pressure, shop towels compulsory. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-24, 14-44 and 14-47.
Unleaded only — the filler neck is sized to accept only unleaded nozzles, and a deflector pushes larger ones away. On blends the manual is clear: ethanol is accepted up to 10 percent (“gasohol”), with the caveat that “due to their generally higher volatility, these blends may adversely affect the starting, driveability and fuel efficiency”; MTBE is accepted up to 15 percent; but methanol is FORBIDDEN — “DO NOT USE GASOLINES CONTAINING METHANOL. Use of methanol/gasoline blends may result in starting and driveability deterioration and damage to critical fuel system components”. On knock, a useful nuance: “occasional trace knock at low engine speeds is not harmful; however, continued knock at high speeds can damage your engine”. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-1, 14-2 and 14-7.
By observing three rules the manual repeats on every page of the chapter. One: squeeze the retainer tabs and pull — and note that “the retainer stays on the nipple” of the component, not on the tube; a tube must never be reconnected without its retainer, on one side or the other. Two: before reconnecting, “apply a light film of clean 30 weight engine oil to the tube end. DO NOT use any other lubricant” — the tubes are plastic and the O-rings like neither grease nor silicone. Three: do not trust the click. “The locking ears and the shoulder on the fuel tube must be completely visible in the windows”, and then pull on the line to verify. Finally, a damaged fitting cannot be replaced on its own: the whole tube must be renewed. And always: filler cap off first, shop towels, eye protection, no flame — tank and tubes are plastic. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-5, 14-6, 14-44 and 14-45.
It is a positive displacement, multi-cell roller pump, single speed, driven by a 12 volt permanent magnet motor and immersed in the tank, integral with the gauge sender. It runs whenever the engine runs. Two internal parts are worth knowing: an outlet check valve with a ball, which “prevents the system from losing prime when the engine is not operating” — that is why residual pressure remains hours after switch-off; and a relief valve that bypasses fuel to the suction side if internal pressure reaches about 689 kPa (100 psi). The moulded plastic tank holds 64.4 litres and contains a reservoir tray: the fuel return empties into it and the pump inlet sits in it, which keeps the pump fed even when the tank level is below the level in the tray. The assembly is certified for a full 360° rollover without leakage. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-3, 14-7 and 14-13.
In both directions, and subtly. Before engagement: the A/C module sends the ECU a “predict” signal 0.5 second before engaging the compressor, so it has time to raise the idle; and it stops sending it 0.5 second before disengaging, to lower it again. So idle does not dip when the air conditioning cuts in — if it does, look at the idle speed regulator or that signal. At full throttle: “when the engine is at wide open throttle, a time when the engine needs maximum power, the ECU sends a signal to the module to disengage the A/C compressor clutch” — for 15 seconds. And on the cooling side, the electric fan runs whenever the compressor is engaged, whatever the coolant temperature. 1990 Eagle Premier / Dodge Monaco service manual, folios 14-22, 14-24, 14-27 and 7-2.
The workshop manual's complete test sheet. Pump: minimum delivery 850 cc in 30 seconds. Primary pressure: checking value 4.9 to 5.5 bar, setting value 5.1 to 5.3 bar. Control pressure warm (regulator above 40 °C): 3.4 to 3.8 bar with the vacuum hoses disconnected, and 1.4 to 1.8 bar with a vacuum pump on the delay-valve regulator (vacuum setting value 450 to 550 mbar). Cold, it is a curve against the radiant temperature at the regulator. Rest pressure: 3.3 bar, and at least 1.7 bar after 10 minutes. Injectors: opening pressure 3.5 to 4.1 bar. DeLorean workshop manual, folio D:02:01.
Line pressure: 450 to 530 kPa (4.5 to 5.3 bar). Minimum rest pressure: 150 to 240 kPa (1.5 to 2.4 bar). The control pressure, though, depends on the regulator fitted — and there are eight types by engine, model year and market: 005, 018 and 038 on E engines; 004, 018, 021, 029 and 066 on F engines. The identification number is stamped on top of the regulator (the last three digits): that is what you read before opening the table. For the 004, for instance, the warm control pressure is 345 to 375 kPa. Volvo CI fuel system booklet, section 2 (23), pages 6 and 7.
Almost, and the differences show. The warm control pressure is nearly identical — 3.4 to 3.8 bar at DeLorean, 3.45 to 3.75 at Volvo with the 004 regulator. The primary pressure shifts a little: 4.9 to 5.5 bar (setting 5.1-5.3) at DeLorean against 4.5 to 5.3 at Volvo. The rest pressure, however, cannot be compared as it stands: DeLorean quotes 3.3 bar then a minimum of 1.7 after ten minutes, Volvo a minimum of 1.5 to 2.4 with no duration. Two test protocols on the same Bosch injection — all the more reason to follow YOUR vehicle's sheet, not the neighbour's. DeLorean workshop manual folio D:02:01; Volvo CI booklet page 6.
It all depends on engine, model year AND market, and the manual gives two tables. E engines, no catalyst: B27E 1975-1977 Sweden and Australia 1.5% (check 1.0-4.0), other markets 2.0; 1978 to 1980 and all B28E: 2.0% (check 1.0-3.0). Idle 900 rpm — 1,000 with automatic transmission. F engines, catalysed: B27F 1976 1.7% (1.4-2.0) with the air pump disconnected; 1977 USA California 0.7% (0.4-1.0), USA Federal 1.0 (0.7-1.3), Canada and Japan 1.7; 1978, 1979 and B28F: 1.0% (0.7-1.3), Lambda sensor disconnected — and once the sensor is reconnected the CO must drop below 1.0%. Idle 900 rpm, 950 on the 1980 B28F. Two general rules: automatic transmission in neutral with the parking brake on, and if the CO is within the check values, do not adjust, even if it is not on the setting value. Volvo CI fuel system booklet, section 2 (23), page 5.
Three, and they are not decoration. Eagle Premier: the fuel tank and fuel tubes are plastic — no open flame, cutting torch included, anywhere near them; and the filler cap must be removed to relieve tank pressure before disconnecting any component. On the quick-connect fittings the retainer is mandatory: “a fuel tube should never be inserted into a quick-connect fitting without the retainer”, and a damaged fitting is replaced together with the whole tube, never on its own. Volvo, on the injector test rig: “never exceed a pressure of 600 kPa (85 psi) during the test”, and the CO gauge adapter nipples can be extremely hot. Finally, when adjusting CO, tool 5102 must be removed or the air-fuel control unit may be damaged. Eagle manual folios 14-1, 14-7 and 14-10; Volvo CI booklet pages 78, 101 and 108.
The manual gives them by diameter, which is rare and very useful on a 5-bar circuit: M8 bolt 10-12 N·m · M10 13-15 · M12 20-24 · M14 15-20 · M12 cap nut 15-20 · M14 cap nut 25-30 N·m. Worth noting too, in the same chapter's repair notes: most of the injection components are sealed and cannot be dismantled. DeLorean workshop manual, folios D:01:16 and D:02:01.
By how long it passes current to the cold start valve, against coolant temperature: at −20 °C the contact opens after 7.5 ± 2 seconds; at 35 ± 4 °C it no longer closes at all (zero time). Two neighbours to check at the same time: the control pressure regulator's delay valve, which must take 10 ± 2 seconds to bleed down from 16 to 8 inches of mercury, and the acceleration enrichment thermal vacuum valve, fully closed above 53 °C and which must start to open at 48 °C as the temperature falls. DeLorean workshop manual, folio D:02:01.
Four pressures, and none of them may be confused with another. Supply pressure: checked between 5.1 and 5.5 bar, set to 5.3 ± 0.1 bar at idle — this is a “high pressure” K-Jetronic, above the ordinary one. Minimum residual pressure, engine stopped: 2 bar after 10 minutes, 1.8 bar after 20 minutes — this is what governs hot restarting. Control pressure, engine warm: 4.4 down to 3.8 bar, at idle as at full load, and 4.2 to 4.6 bar at 1,600 m altitude — this version's regulator has no manifold pressure correction but a built-in altitude correction. Main injectors (no. 77 00 266 204): opening between 3.9 and 4.5 bar, leak-tight down to 2.5 bar, spray angle 35°. Bosch lambda sensor 77 00 708 605: 720 to 1,160 mV on a rich mixture at 350 °C, 150 to 175 mV on a lean one at 250 °C. M.R.249, NT 1205 E supplement, page 5.
With an ohmmeter, engine cold or stopped, connector unplugged, across the valve's two terminals. 2 to 3 Ω: the valve is correct. 0 to 0.5 Ω: internal short circuit — replace it. Open circuit: winding broken — replace it. Three readings, three verdicts: this valve is not repaired, it is measured. It sits in the middle of the V, between the hydraulic head and the fuel return hose to the tank, and it is what trims the mixture on the computer's orders. M.R.249, NT 1205 E supplement, pages 15 and 45.
Pressure-jump switch — unplug its connector and the hose linking it to the 3-way thermovalve, ohmmeter across the terminals, and apply 300 mbar of vacuum with a hand vacuum pump: you must read 0 to 0.5 Ω. Then let the vacuum fall: at 80 mbar the circuit opens (∞). The rule fits in two lines — above 80 mbar: 0 to 0.5 Ω; below: ∞. Full-load switch — slip a 2 mm shim between the safety stop and the full-load stop, then adjust the switch on its two screws so that resistance is zero at e = 2 mm. Table: gap greater than 1.5-2 mm → ∞; smaller → 0 to 0.5 Ω. ⚠️ A reading note: page 15 of the same document says this switch suppresses mixture regulation “beyond a throttle opening of 50 °C”. It is a unit misprint, and the manual supplies the proof itself: its page 21, describing the same switch, correctly reads “from 50° of throttle opening”. A throttle opening is measured in degrees of angle. Running check: engine warm (two cooling fan cycles), oxygen sensor up to temperature, at idle, operate the full-load switch by hand — the integrator voltage must then lock at about 6 V; if not, check the switch and its connection to terminal 12 of the computer. M.R.249, NT 1205 E supplement, pages 15, 21, 48 and 60.
In two stages, neither of which needs a diagnostic case. By hand, valve removed: give the valve a quick twist in both directions — it must open and close. A plug that sticks mechanically is found before anything electrical is suspected. Under voltage, connector unplugged: feed terminal 4 with 12 V, then earth one terminal for a brief instant. Earth terminal 5: the valve must close — and with the engine running, the speed must drop clearly below 825 rpm (750 rpm with the automatic gearbox). Earth terminal 3: the valve must open — and the speed must rise above 1,500 rpm. Two gestures, two unmistakable results on the rev counter: a valve that answers both is a good valve, and the fault lies with its control. Running check with the connector in place: lift its rubber boot and measure between earth and the terminals — 12 V on terminal 4, and on terminals 3 and 5, depending on the meter, either a steady intermediate voltage between 0 and 12 V or a voltage cycling between 0 and 12 V. ⚠️ And above all, do not transpose to the Alpine A610: same three-terminal valve, same 12 V on terminal 4, but opposite roles — a brief earth on terminal 3 and the valve closes, speed dropping clearly below idle; on terminal 5 it opens and speed rises above 2,000 rpm. The A610's manual boxes one more warning: never feed 12 V to the computer side of the connector, which destroys it on the spot. The catalysed R25 V6 Turbo follows the A610, not the injection R25: terminal 3 closes, terminal 5 opens and speed exceeds 2,000 rpm, with the same warning. M.R.249, NT 1205 E supplement, page 36 · N.T.1150 annexed to M.R.249, page 11 · Alpine M.R.297, folio 17-15 · Technical note 1558, folio 17-13.
With a test lamp and three shims — and the check is a go/no-go that leaves no room for interpretation. Setting: connect a test lamp between contacts 1 and 4 of the micro-switch, slip a 1.3 mm feeler gauge between the adjusting screw and the throttle stop, and screw the micro-switch's adjusting screw in until the lamp lights; lock it with its nut. Check: with a 1.2 mm shim, the lamp must light; with a 1.6 mm shim, it must not. The switch therefore changes state within that four-tenths window. ⚠️ Those are the values of the catalysed car's supplement. The September 1985 note for the non-catalysed 1986 model prints other values on the same drawings: setting shim 0.3 mm, check 0.2 mm (lamp lights) and 0.6 mm (lamp stays off), and a linkage clearance of 0.1 mm instead of 1 mm. Neither document says whether this is a change or a misprint: read the note that matches the car. It also gives a check without a lamp — ohmmeter between terminals 2 and 7 of the diagnostic socket, ignition off: 0 Ω with the throttle on its idle stop, infinite with the throttle slightly open. The three wires: black = earth; yellow = throttle-opening contact, to the advance solenoid valve; green = foot-off contact, to the computer. Before any of this, the linkage itself: a 2 mm shim (or tool Mot. 843-08) between the idle stop and the safety stop, and the rod length set for a 1 mm clearance between adjusting screw and throttle stop — the rod has a right-hand and a left-hand thread, the left-hand end marked by a groove on the ball joint. And the accelerator cable is set so that, pedal floored and throttle wide open, the compensating spring is compressed by 2 mm. M.R.249, NT 1205 E supplement, pages 34 and 35 · N.T.1150 annexed to M.R.249, pages 9 to 11 and 17.
With an ohmmeter, engine stopped, and each has a closed state and an open one. The 15 °C thermo-contact — below 15 °C, with the airflow meter's connector and the full-load switch unplugged, measure on the wiring side of the full-load switch connector (or across terminals 12 and 16 of the removed computer's connector): 0 to 0.5 Ω below 15 ± 3 °C, open circuit above. The “60 °C” thermo-contact — engine stopped, below 55 °C, computer disconnected, measure between terminal 7 of the diagnostic socket and terminal 7 of the computer connector: 0 to 0.5 Ω below 56 ± 3 °C, open circuit above 61 ± 3 °C. Note the figures: the part called “60 °C” actually switches between 56 and 61 °C, with a hysteresis between closing and opening — so a reading taken at 58 °C can legitimately go either way, and proves nothing. Measure it clearly below and clearly above. M.R.249, NT 1205 E supplement, page 47.
With four screws, a voltmeter and a CO analyser on each manifold — and in an order that has to be kept. The screws: C is the air by-pass (idle speed), D the total enrichment, A and B the balance between banks. ⚠️ A trap before you start: here screw A acts on the right bank and B on the left — these are callout letters on the drawing, not the bank letters, where bank A is the left one. Preset: screw A, B and C fully in, then back each out 2 turns. Tachometer, and voltmeter on the integrator output (terminal 8 of the diagnostic socket, terminal 2 to earth); a CO take-off screwed into each manifold. Warm up to the second fan cycle. Earth terminal B of the idle computer to block the regulation, and set screws C for 825 ± 25 rpm. If screw C cannot reach the right speed at either end of its travel, open it 2 turns again and increase or reduce the throttle passage with the stop screw (5) — in which case the idle switch and gear selector settings must be checked. Release terminal B: the speed must peak at about 1,300 rpm then settle at 900. Set total enrichment with screw D — 3 mm hex key Mot. 843-09, no pressure on the tool, in to enrich, out to weaken, the opening plugged while reading — for a mean integrator voltage of 6.5 ± 0.5 V. Disconnect the oxygen sensor (the integrator then holds at about 6 V), and bring each bank to 0.7 to 1% CO with its balance screw. Reconnect the sensor, earth B again, check 800 to 850 rpm, release B, and confirm the integrator really sits between 6 and 7 V. Last, and not optional: refit the tamper-proof caps — the plug over screw D is required by law in some countries — and check the manifold blanking screws are perfectly tight. M.R.249, NT 1205 E supplement, pages 50 to 52.
By comparing the CO before and after it — the most direct test the manuals give. Analyser at the tailpipe; measure cold, then warm the engine until the fan has cut in twice: warm, tailpipe CO must be close to zero. If it exceeds 0.2%, check the integrator voltage across terminals 2 and 8 of the diagnostic socket, and follow the three-way fork the manual draws. Integrator and oxygen sensor both correct: replace the converter. Integrator incorrect: replace the oxygen sensor, not the converter. Integrator correct, and the CO measured upstream of the converter equal to the CO at the tailpipe: the converter is converting nothing — replace it. The upstream figure is easy to get on this car, since each manifold carries a plugged take-off for the analyser. One warning the manual repeats: CO fluctuations do not always show at once, and can be erratic, because the reading varies with the analyser used — sensitivity, response time, filter condition, hose length. On the catalysed R25 V6 Turbo the method differs, and runs through unplugging the sensor instead. M.R.249, NT 1205 E supplement, page 11 · Technical note 1558, folio 19-6.
Because it is designed to. During a cold start and warm-up, the regulated idle speed fluctuates and can climb to 1,200 to 1,500 rpm with the coolant at 0 to 20 °C, driven by the engine's water temperature sensor: the idle regulating valve is supplying the extra air the engine needs to pull away. A high cold idle on this car is not a stuck throttle. Once warm, and when the regulation is not active, the computer holds the speed at 900 ± 25 rpm. Two further behaviours that look like faults and are not. With the ignition on and the engine stopped, the computer OPENS the valve, and the valve stays open throughout starting; only once the engine exceeds the set speed does the computer start closing it, until it finds the balance position matching the air the engine needs at idle. And below 60 °C of coolant, no idle adjustment is possible — trying to set idle on a half-warm engine is wasted effort. And a check by ear, before any instrument: engine cold, as the ignition is switched on, you should hear the valve positioning itself. If it stays silent, check the valve, its electrical circuit and its connections. The valve itself sits on the right-hand manifold, flywheel side; it has two windings, fed by periodic signals, which position its plug anywhere between fully open and fully closed over a maximum rotation of 90°. Not to be confused with the Safrane V6's Hitachi valve, which has a single winding and is closed at rest. M.R.249, NT 1205 E supplement, pages 19 and 60 · Safrane M.R.302, chapter 17.
By acting on pressure, not on the injectors — and the manual of the catalysed export R25 V6 (B29A — Germany, Austria, Switzerland) explains it plainly. On a K-Jetronic, the quantity injected depends on the differential pressure across the metering slits of the fuel distributor. Lower the pressure in the distributor's lower chambers and the differential rises, so more fuel flows. To do that, the lower chambers are fed in parallel with the supply circuit through a calibrated orifice — and, the manual stresses, this device does not exist on the standard K-Jetronic distributor. A second restriction links the lower chambers to the fuel return, and this one is adjustable: open, the chamber pressure falls; closed, it returns to supply pressure. That adjustable restriction is a solenoid valve, the frequency (duty-cycle) valve, switched rapidly open and shut by the lambda computer, so that the chamber pressure is proportional to its opening and closing times. The practical consequence: the distributor of the catalysed car is a specific part, not interchangeable with that of a non-catalysed K-Jetronic. The sensor behind it: a ceramic that conducts oxygen ions from about 250 °C, whose output jumps by 800 mV either side of lambda 1 — the stoichiometric mixture, which the manual gives as one gram of fuel for 14.8 g of air. The loop does not regulate at full load, nor during starting and pulling away until the sensor is hot. Around it the computer adds its own strategies: acceleration enrichment via the pressure-jump switch — none above 55 °C of coolant; cold enrichment below 15 °C; a cold-start injector timed by the time-delay thermo-contact; and the full-load switch cutting the regulation from 50° of throttle opening. M.R.249, NT 1205 E supplement, pages 18, 20 and 21.
Because the manual boxes the instruction as IMPORTANT: “on V6 vehicles with Bosch K(E) injection fitted with a catalytic converter, the quantity of fuel when driving should not fall below 7 litres — otherwise mixture-formation disturbances may occur which impair the converter's efficiency”. Running on the reserve is therefore not a harmless habit on this car: a pump drawing air in corners leans out the mixture in bursts, and it is the converter that pays. The same page describes the filler that goes with it: a smaller-diameter opening than a leaded-fuel nozzle, a flap closing the opening, and a label inside the fuel flap in three languages — English, French, German — prescribing unleaded fuel exclusively. M.R.249, NT 1205 E supplement, page 9.
The converter — and the pipe in front of it. The manual is precise: “if non-unleaded fuel has been used, the exhaust pipe upstream of the converter must be replaced with a new pipe (where the downpipe and the converter are two separate parts)”. The pipe carries lead deposits that would poison the new converter from its first kilometres. Before any replacement, the fuel in the supply system must be rid of lead: either flush the system with unleaded, or fill the car up with unleaded several times over. What lead does is worth knowing, because it is not instant: the converter's precious metals — platinum or palladium — are not destroyed at once by small quantities, “but there is always overheating. This can reach such a degree that the cell structure is destroyed by decomposition and no longer lets exhaust gas through”. A converter poisoned by lead therefore ends up blocking the exhaust, not just failing to clean it. And on reassembly, the line must be perfectly sealed from the manifold gasket to the converter, included, with every gasket removed replaced. M.R.249, NT 1205 E supplement, page 10.
No — and there are four figures, not one. On the 1986 model year B 298: manual gearbox — 900 ± 25 rpm with idle regulation, 825 ± 25 without; automatic, selector in neutral — 750 ± 25 with, 675 ± 25 without. CO is 1 ± 0.5% per cylinder bank, with a maximum allowable deviation of 0.5% between the two. The manual sets its conditions before any measurement: engine run in, air filter fitted, ignition in perfect order and correctly timed, and no leak on the brake vacuum take-off, the ignition, the fuel supply, the crankcase breathing or the automatic gearbox. N.T.1150 annexed to the M.R.249, its page 14 (page 81 of the PDF).
By the September 1985 technical note 1150 — and not quite like the catalysed version. Engine warm, meaning after the cooling fan has come on and gone off once. Preset: screw the three screws A, B and C fully in, then back A and B out two turns; idle speed is then found with the air by-pass screw C. The CO take-off valves are set so both banks can be read at once. a) Block the regulation: earth terminal 10 of the idle computer, or clamp the hose between the regulating valve and the air distributor with a Mot. 453-01 clamp. b) Start the engine and set idle with screw C: 825 ± 25 rpm with the manual gearbox, 675 ± 25 with the automatic in neutral. c) Set total CO with screw D: 1 ± 0.5 %. d) Reset idle with screw C if needed. e) Equalise the two banks' CO with screws A (right bank) and B (left bank). f) Check that total CO and idle are still within tolerance, otherwise correct. g) Remove the earth from terminal 10 or the clamp, and check 900 ± 25 rpm (750 ± 25 automatic), CO 1 ± 0.5 % on each bank. Screw D is turned with the 3 mm hex key Mot. 843-09, without pressing, in to enrich; it is only reachable after removing the security plug (l) and loosening the sealing screw (m). IMPORTANT: during CO measurement, the sealing screw (m) must be fitted, or the hole closed with a finger. After setting, refit caps and plug — the plug over screw D is legally required in some countries. What differs on the catalysed version (NT 1205 E): screw C is also backed out two turns at the preset, and the mixture is set against the integrator voltage, with 0.7 to 1 % CO per bank. N.T.1150 annexed to M.R.249, pages 15 and 16 · M.R.249, NT 1205 E supplement, pages 51 and 52.
Four parts in four places — and one of them means taking the air distributor off. The system, introduced for the 1986 model year and identical to the Renault 25 GTX's (B 29E), replaces the auxiliary air slide with an electronic computer, a coolant temperature sensor (to take account of a cold or warm engine) and a micro-switch that reports the throttle position; the regulation itself has no adjustment. The regulating valve is fixed on the flywheel side of the right-hand air distributor: unplug its connector, loosen the clamps and remove its two hoses, then its screws and the two screws of its clamp on the distributor. IMPORTANT on refitting: respect the fitting direction — the arrow on the valve base shows the air flow — and route the hoses without strain. The computer is mounted with the ignition computer on a plate against the left front wheel arch, under a plastic housing that keeps dirt and knocks out: housing screw and clip, the computer's two screws, and mark its connectors — 5-way at the bottom, 6-way at the top. The micro-switch: mark its wires' positions before unplugging, then two screws. The coolant temperature sensor sits on the left, flywheel side, on the coolant distribution pipe — and it is the long one: first free, among other things, the fuel lines at the fuel distributor, the throttle control, the crankcase breathing, idle regulation, ignition vacuum and idle stabilisation hoses, and the unions of the control pressure line, the injector lines, the tank return and the cold start valve; then remove the HT leads, the lower housing, the intermediate housing, the injectors, the cold start valve, the auxiliary air hose and the air distributor. Refit in reverse order, renewing every gasket. N.T.1150 annexed to M.R.249, pages 1, 5 to 8.
Two connectors. X, 5-way: 1 + after ignition · 2 earth · 3, 4 and 5 to the regulating valve · 6 free. Y, 6-way: 7 air conditioning information · 8 to the idle micro-switch · 9 and 11 to the coolant temperature sensor · 10 earth for the idle regulation · 12 engine speed pulse information. Terminal 10 is the one the setting method earths to block the regulation. Terminal 7 is checked with the air conditioning on: engine warm, idling, A/C switched on and compressor clutch engaged, voltage must be present on terminal 7; then, rev counter connected and the compressor under load (watch its cycle), idle must hold 900 ± 25 rpm with the manual gearbox. With the automatic, the same in neutral — but in “D”, the table expects no voltage on terminal 7 and 750 ± 25 rpm. Otherwise, check the circuit; if it is sound, check the computer's and valve's connections and operation, and the idle setting. The wiring diagram names the rest of the system: 513 coolant temperature sensor, 559 regulating valve, 515 micro-switch, 275 computer; D the TDC sensor, E the cold start valve information, F the injection “running engine” feed (speed relay, fuel pump), G the idle stabilisation solenoid valve. N.T.1150 annexed to M.R.249, pages 12, 13 and 19.
No — two pins are swapped. On the R25 V6 injection the socket sits on the right-hand air distributor. The 1985 note lists: 1 TDC sensor signal · 2 distributor earth · 3 contact breaker · 6 + coil · 7 idle switch check · 10 + injection check, engine running · 12 cold start valve earth · X-Y centring pins. The catalysed car's supplement adds 4 TDC sensor signal, 5 TDC sensor shielding and 8 integrator voltage check. Two uses the note spells out: ohmmeter between 2 and 7, ignition off, to check the idle micro-switch (0 Ω at idle, infinite throttle slightly open); voltmeter between 10 and 12 to check the cold start valve. Now the Renault 30's socket, also twelve pins: 1 pulse generator · 2 earth · 3 breaker A · 4 + coil · 5 shielding · 6 pulse generator. Pins 1, 2, 3 and 5 match; 4 and 6 are swapped — + coil on 4 on the R30, on 6 on the R25. A lead read off the wrong car's table lands on the wrong circuit. N.T.1150 annexed to M.R.249, pages 11 and 17 · M.R.249, NT 1205 E supplement, page 35 · Renault 30 M.R.167, folio C-10.
With the note's check table, one line per function. Idle switch — ohmmeter between terminals 2 and 7 of the diagnostic socket, engine stopped: throttle on its idle stop 0 Ω, throttle slightly open infinite; otherwise check the micro-switch and its setting, then the wiring (lead to earth). Cold start valve — voltmeter between terminals 10 and 12, engine cold, coolant below 45 °C, while cranking: a limited voltage through the thermo-time switch, printed as “between 15 and 25 °C, time 5 to 2 s”; if there is none, check the thermo-time switch's connections, then the switch itself. Ignition timing — engine warm, idle below 1,000 rpm, vacuum capsule hose clamped: 10° ± 2 at the flywheel, otherwise set to 10°. Vacuum advance — hoses as in the diagram, connection to manifold vacuum through a filter; engine warm (above 45 °C), gauge and voltmeter: at idle, no vacuum at the capsule and timing 10° ± 2; at about 2,000 rpm, vacuum present. With an advance meter: 10° in the first case, 28° minimum in the second. If not, measure the voltage at the solenoid valve's terminals and check the valve or its feed. Idle stabilisation — engine warm, accelerate slightly and let it return to idle without touching the pedal: between 1,000 and 1,500 rpm, then normal idle after a delay of 3 seconds; otherwise check the relay's connections, the time relay, and the pneumatic circuit between solenoid valve, manifold and ignition vacuum capsule. N.T.1150 annexed to M.R.249, pages 17 and 18.
With a rev counter, from cold to hot. Engine cold, ignition switched on: you must hear the valve positioning itself; if not, check the valve, its circuit and its ancillaries. On starting: speed between 1,500 and 2,000 rpm, which must fall continuously to idle as the engine warms up — otherwise check the computer, the coolant temperature sensor, the micro-switch, the supply lead and the speed pulse information. (The same note prints 1,200 to 1,500 rpm for coolant between 0 and 20 °C in its description of operation.) Engine warm, after the cooling fan has cut in: idle too high → check the micro-switch's operation and setting, the throttle control setting including the cable, the idle setting without regulation (speed and mixture), the tightness of the intake systems, the coolant sensor, the valve, the wiring and the computer's conformity; idle too low → check the idle setting without regulation, the valve's air circuit (hoses blocked or crushed), the micro-switch, the valve — replaced if faulty — the circuit, and the computer, replaced if faulty or non-conforming. The same table checks the K-Jetronic's control pressure regulator: at idle, before any idle setting, CO below 4 % — or, with a gauge, between 3.4 and 3.8 bar at idle, and with the manifold-to-regulator hose clamped or plugged the pressure must drop by 0.4 bar; otherwise check fuel pressure, the regulator's supply voltage and its pneumatic connections. N.T.1150 annexed to M.R.249, pages 5, 19 to 21.
Through a double circuit, before and after the throttle. From the 1986 model year, the oil vapours from the block are led from the rocker covers two ways: to the air duct housing at the airflow meter (the circuit before the throttle) and to the air distributor (the circuit after it), with a Ø 2.75 mm calibration, before reaching the combustion chambers; the diagram also shows an oil separator and a return hose to the sump. The same model year brings a side-mounted air filter, identical to the Renault 25 V6 Turbo's: element renewed every 20,000 km; release the straps, then the clips that hold the cover on the housing; refit in reverse, and — the note's only remark — make sure the filter's centring pins are correctly aligned in its holder. All of this applies to Europe, except Switzerland. N.T.1150 annexed to M.R.249, pages 1, 3 and 4.
Because a V6 has two banks, each with its own metering, and a single reading at the tailpipe averages them. The manual fits each manifold with a take-off closed by a plug; the Mot. 844 tool replaces both plugs with two rigid lines joined by a three-way valve to the analyser, so each bank can be read separately. The tolerated deviation between the two is 0.5% CO, measured at 825 ± 25 rpm. Without this, a rich bank offsetting a lean one gives a perfect overall CO on a car that is anything but. And for the take-off to be gas-tight, the probe normally connected to the analyser is unplugged and connected to the three-way valve instead. N.T.1150 annexed to the M.R.249, its page 14 · M.R.249, NT 1205 E supplement, page 5.
By eliminating everything upstream first, and the order matters. Engine brought up to temperature — until the cooling fan has cut in and out twice — analyser at the tailpipe, readings taken between 2,000 and 3,000 rpm, waiting for the values to steady. If CO exceeds 0.5%, unplug the lambda sensor. If the CO is the same with the sensor plugged in and unplugged, the sensor is not regulating anything — check it on the XR25 with #05, watching bargraph 13 fluctuate between 2,500 and 3,000 rpm. ⚠️ And before replacing anything: run a lead test at the exhaust to confirm the tank holds unleaded. If leaded fuel has been through the car, the system must be flushed by filling the tank completely with unleaded several times over BEFORE fitting a new sensor or converter — otherwise the new part is poisoned like the old one. ⚠️ The speed range is not the same everywhere: 2,000 to 3,000 rpm on the R25 V6 Turbo, 2,000 to 2,500 rpm on the Alpine A610, whose manual also simply asks you to wait until the cooling fans cut in. The Safrane V6 goes further in the checks on the converter itself: fan cut in twice, analyser at the rear, 2,000 to 2,500 rpm, CO below 0.5 %; above that, bar graph line 8 and the variations of # 05 at a steady 2,000-2,500 rpm, sensor connected — replace the sensor if the test is wrong and repeat both the CO test and the lead test. If the sensor is sound, or a new one still leaves CO above 0.5 %: the converter must make no noise when shaken, car stopped (and when moving); once removed, no visible damage, no noise when shaken, not partly or completely blocked, and not poisoned by lead. Before replacing a converter or an oxygen sensor, lead test at the exhaust; if positive, rinse with at least two tankfuls of unleaded. Technical note 1558, folio 19-6 · Alpine M.R.297, folio 19-10 · Safrane M.R.302, chapter 19.
Two, and they are not the same. A single-barrel Solex 34 TBIA (marking 838) and a twin-barrel Solex 35 CEEI (marking 839). Light throttle is fed by the single-barrel alone; the twin-barrel comes in afterwards. Hence the jetting, where the single-barrel carries two circuits the other does not have — a constant-CO jet and an enrichment jet. The table: venturi 28 against 27/27 · main jet Gg 130 against 145/145 · air correction A 145 against 150/150 · idle jet g 42 against 47.5/47.5 · constant-CO jet gco 35, none on the twin · enrichment 80, none on the twin · throttle angle relative to the closed butterfly 2°30′ against 0°45′ · pump jet D 50 against 60 · float setting 38.5 mm on both · gauge number 71644007 and 71644037 · ball needle valve 1.5 and 1.7 · accelerator pump travel 5 mm, cam-driven on the twin. Alpine M.R.273, folios B-29 to B-34.
The same two carburettors, and not the same calibration. Both cars run a single-barrel Solex 34 TBIA alongside a twin-barrel Solex 35 CEEI — but the index number stamped on the body is what decides the jets, and they differ. On the Renault 30 the single-barrel comes in two versions, 620 and 647, and the twin-barrel is 97; on the Alpine GTA they are 838 and 839. Even within the Renault 30 the two single-barrels differ, on one jet: main jet 130 on the 620, 127.5 on the 647, everything else alike — venturi 28, air correction 145, idle jet 42, pump jet 50, 1.5 ball needle valve, 5 mm pump travel. The 35 CEEI 97: venturi 27/27, main jets 145/145, air correction 150/150, idle 47.5/47.5, pump jet 60, 1.7 needle, cam-driven pump. So ordering “a carburettor for a PRV V6”, or a jet kit, means nothing: it is the number on the body that answers. Renault 30 M.R.167, folio B-70 · Alpine M.R.273, folio B-34.
In two stages. The throttle cable turns a drum, and a rod opens the throttle of the single-barrel 34 TBIA. Once the drum has turned 30°, a driver pushes a lever, whose rod moves left and frees a stop pin: the throttles of the twin-barrel 35 CEEI are released — and they open when the vacuum taken at the venturis of both carburettors is enough for the membrane of the pneumatic device. Releasing the pedal turns the drum back and both rods close both carburettors. Idle — engine warm, air filter fitted, ignition sound and set, no extra air (a leaking vacuum advance hose or the automatic's vacuum capsule, for instance), rev counter connected. Idle only slightly off: bring it to 875 to 925 rpm with the air screw (A) of the 34 TBIA alone. After a carburettor overhaul or with a wrong mixture: screw A and B in alternately to 680 to 700 rpm — without ever screwing them fully home; then unscrew them alternately until about 960 to 980 rpm, in steps of about 50 rpm, always starting with A and finishing with B; screw B back in until idle drops by about 60 rpm; and finally set idle with A to 875 to 925 rpm, aiming for a smooth-running engine. Checks: 34 TBIA cold start, air filter off — on a cold engine (6 hours after stopping, at 15 to 20 °C) the choke flap must be closed and there must be a clearance J of several millimetres between the throttle stop screw (1) and the throttle lever (L); on starting the flap must open slightly at once (manifold vacuum on the membrane), then open fully as the engine warms, the clearance closing up until, warm, the lever rests on the screw. 35 CEEI pneumatic opening, engine stopped: connect the diagnostic centre's vacuum hose to capsule (T), apply 30 to 40 mm Hg, open the 34 TBIA's throttle with rod (M) — rod (11) must move left and free the stop pin of the two toothed sectors (N), and both throttles must then open under the vacuum. The Alpine V6 GT keeps the same two-stage control with one extra part: a thermovalve in the coolant circuit that warms the choke cuts the vacuum to the membrane while the coolant is below 43 ± 3 °C — the twin-barrel cannot open on a cold engine. Beside the Alpine V6 GT and its 800 to 850 rpm with an analyser, the R30 is set with a rev counter, a hundred rpm or so higher. Renault 30 M.R.167, folios B-69 and B-71 · Alpine M.R.273, folios B-33 and B-42.
Because the choke is driven by a thermo-element, and the manual says so in a box: after removing the carburettor, wait about an hour before checking or adjusting anything, so the thermo-element has settled at room temperature. Then read the table for that temperature. Throttle angle H: 4.40 whatever the temperature — measured on the bench with intermediate plate Mot. 522-02 and gauge Mot. 522, throttle rod (16) disconnected, a counterweight on the throttle spindle nut; the dial gauge is zeroed on the lower side of the throttle, the knurled ring turned 180° to the higher side, and H is the difference, adjusted with stop screw (1). Dimension X, with a vernier, adjusted by reaching screw (V) with a screwdriver through opening (P) above the vacuum capsule: 28.5 at 15 °C, 27.9 at 20 °C, 27.3 at 25 °C, 26.6 at 30 °C. Minimum throttle opening, with gauges MS 532, adjusted at screw (2): 85 / 80 / 75 / 70 for index 620, 95 / 90 / 85 / 80 for index 647. Pneumatic choke flap opening: 4.6 / 5.5 / 6.6 / 7.9. The manual prints no units for these columns. The two 34 TBIA indexes of the R30 thus differ on the minimum opening as well as on the main jet (130 on the 620, 127.5 on the 647). The Alpine V6 GT's base manual prints the same table, value for value, with only the index 620 column — although the GTA fits a 34 TBIA index 838; and its D501 update replaces it with another method. Renault 30 M.R.167, folios B-70, B-72 and B-73 · Alpine M.R.273, folio B-36 and D501 update, folios B-36a and B-37a.
Choke of the single-barrel 34 TBIA, air filter off. Engine truly cold — 6 hours after stopping, at an ambient 15 to 20 °C — the choke flap must be closed, and there must be a clearance J of several millimetres between the throttle stop screw and the throttle lever. Start the engine: the flap must open slightly straight away, pulled by engine vacuum on the membrane, then open fully little by little as the engine warms, while clearance J closes up; engine warm, the lever rests on its stop screw. Twin-barrel 35 CEEI: its two throttles are opened by vacuum, not by the cable. Engine stopped, connect a vacuum source to capsule T and draw 40 to 55 mbar (30 to 40 mm Hg); open the 34 TBIA's throttle by its rod: the linkage must move aside, free the stop pin of the two toothed segments, and both throttles of the 35 CEEI must then open under vacuum. For bench settings, carburettor removed, wait about an hour so the thermostatic element takes the room's temperature, because the figures depend on it — from 15 to 30 °C, dimension X goes from 28.5 to 26.6, the minimum throttle opening column from 85 to 70 and the pneumatic choke gap column from 4.6 to 7.9 (the table does not give units for these last two). Synchronisation: with the drum at full opening, stop against the 23.4 mm disc, the 34 TBIA's throttle must be wide open — otherwise adjust the length of rod 8. Alpine M.R.273, folios B-35 and B-36.
It replaces the room-temperature table with fixed values; the float and throttle-angle steps stay as they were. The base manual (folio B-36) had you wait an hour and read X, minimum opening and pneumatic choke gap for 15 to 30 °C. The replacement pages B-35a to B-37a do it in order, with a NOTA first: the throttle housing base must be properly centred and fixed on the 34 TBIA for every setting. 1 — Float: top upside down on a plate, with gasket J fitted and the needle ball pressed, B = 38.5 ± 1 mm; the needle clip (E) faces the cold-start device; gauge SOLEX 71 644 007, always with a little play. 2 — Throttle angle: rod (2) disconnected, SOLEX angle gauge and counterweight fitted, plug removed, screw (1) backed off until the throttle closes and wound in to 2°30′; the screw's factory black cap is replaced by a white one once it has been moved. Then, for the rest: bring the carburettor to about 60 °C, and start the settings once its temperature has stabilised at 22 °C. 3 — Minimum throttle opening: gap between lever 3 and the flap spindle 4, 0.6 ± 0.1 mm, set with a screwdriver through hole P above the pneumatic capsule, into the spring. 4 — Throttle angle (cold): SOLEX gauge, screw 5 to 19°. 5 — Choke flap gap: first the mechanical gap — simulate vacuum with pliers, rod 6 home in the capsule, 5.5 mm gauge at the top of the flap, set at lever 7; then the pneumatic gap — rod 6 still home, act on lever 8 to free the pin of lever 12 resting on lever 7 (lever 12 must not touch lever 3), 7.5 mm gauge, set with screw 9; and the weakening device — a 3 mm spacer under throttle lever stop 8 so flap 10 is square to the base, 8 mm gauge, set at lever 3. The 35 CEEI's page (B-38a) keeps its values — float A = 38.5 ± 1 mm, gauge 71 644 037, throttles at 0°45′, needle clip facing the air intakes — as in the base manual. Alpine M.R.273, folio B-36 and D501 update, folios B-35a to B-38a.
Few, and the manual says so plainly for the twin-barrel: “no further adjustments are to be made on the carburettor; the mixture was set at the factory”. What is set: 34 TBIA float — top half upside down on a flat plate, gasket fitted and needle ball compressed, B = 38.5 ± 1 mm, the needle valve clip facing the cold-start device (SOLEX gauge 71 644 007, which must always show a little clearance). 34 TBIA throttle angle: SOLEX angle gauge and counterweight on the spindle, screw 1 backed off until the throttle closes, then turned in until it opens by 2°30′. ⚠️ That screw is sealed at the factory by a BLACK cap; “if the screw is moved, the black cap must be replaced by a WHITE cap” — a white cap therefore tells you the setting has been touched. 35 CEEI throttles: the edge must just cover the transition slot; screw C backed off until the throttle closes, then turned in to open it by 0°45′, and the same on the second one with screw D. Air correction jets: on the 35 CEEI it is fixed, at right angles to the atomiser carrier; on the 34 TBIA it can be removed and needs no particular orientation. Alpine M.R.273, folios B-37 and B-40.
Only once nine conditions are met — the manual underlines them, “to obtain a stable CO between two service checks”. Car run in, at least 1,000 km; cold-start device not working; engine at normal temperature, reached by running at 2,000 rpm until the thermostat opens — idling it warm “would falsify the CO measurement”; idle speed to specification; clean air filter element; ignition correctly set; no extra air getting in; no major exhaust leak; and no big electrical consumer on — heater fan, headlights, heated rear window. Then, with an analyser: screw A (volume) for an approximate idle, screw B (mixture) for the CO, screw A again for the idle — 800 to 850 rpm and 1 to 1.5% CO. On ECE cars screw B carries a tamper plug: white or transparent, fitted in position 1 and locked to the screw; after the setting at the 1,000 to 3,000 km service it is pushed into position 2, where it turns freely without moving the screw, and every later setting calls for a new plug, part no. 77 01 200 829. Fast idle last: engine at 85 °C, capsule disconnected, clearance J = 1 mm between lever and segment with screw 1; capsule then connected directly to the throttle's vacuum take-off, and fast idle set with screw 2 to 1,100 −0/+50 rpm. On the “Swiss” version, the functional check uses 1% ± 0.5 CO. Alpine M.R.273, folios B-41 and B-42 · D501 update, folio B-44a.
In the FRONT luggage compartment, under the boot cover — and the detail that follows from it catches people out: the tank has its own breather, so the filler cap has no vent hole. Fitting a vented cap from another car is therefore a mistake. Feed is by an electric pump driven through a speed-dependent control relay, placed under the dashboard to the right of the steering column: the pump only runs while the engine turns, which is the safety feature of the arrangement. Pump figures: maximum delivery at zero pressure 100 l/h, maximum pressure at zero delivery 0.34 to 0.4 bar — a carburettor pressure, not an injection one. Fuel filter every 50,000 km, and a return line to the tank. Alpine M.R.273, folio B-28.
Idle 700 rpm ± 25 and CO 1% ± 0.25 — a tighter CO window than the 1 ± 0.5% the Renault 25 V6 allows. Fuel pressure regulator: 3 bar −0.2 at atmospheric pressure, 2.5 bar ± 0.2 under 500 mbar of vacuum. Solenoid injectors: 12 volts, 2.5 Ω ± 0.5. And one service interval that stands apart: the paper air filter is replaced every 15,000 km, against 20,000 km on the R25 V6 Turbo and on the A610. Two turbocharged V6s from the same family, and the Alpine asks for its air filter twice as often — a mid-mounted engine breathing from the rear wings does not take in the same air as a front-engined saloon. Alpine M.R.273, D501 update, folio B-49a.
Injection “R”, computer 60 01 007 988 (homologation 60 01 007 574, S 100 802 102), diagnostic code 100 — 101 with memory cassette no. 4 — with idle regulation; it sits in the passenger compartment, in the middle of the rear backrest, reached by releasing and lifting the backrest's centre section. Unlike the A610's, its dashboard warning lamp works: it must light with the ignition on, engine stopped, and go out as soon as the engine runs; lit while driving, it signals an injection fault. CO: with electric idle regulation there is no volume screw, so idle speed cannot be set — only the mixture. Remove the tamper plug over screw (B) of the idle mixture potentiometer; engine warm, after the cooling fan has switched off, set the CO with screw B to the specified value (1 % ± 0.25); refit the plug in (C) — part 77 01 200 832. And a diagnostic trick printed in a NOTA: if even at the end of screw B's travel the mixture cannot be set, pull the crankcase breather hose off the rocker cover — if the mixture becomes more than 1 % leaner, the engine oil must be changed. The components on the engine: ignition power module, electric boost sender, safety pressure switch, manifold pressure sensor, and the CO potentiometer. Alpine M.R.273, D501 update, folios B-49a, B-55a and B-63a.
The advance curves are stored in the injection-ignition computer, which sends a 5 V control signal to the ignition power module; a distributor shares the high tension out in the order 1-6-3-5-2-4. The module's connectors are not wired like the A610's: three-way — A battery +, B earth, C rev counter (free on the A610); two-way — A computer earth (free on the A610), B control signal. Distributor: remove its clipped protective cap, then the cap (3 screws); check the electrodes and carbon brush, the rotor at 0.8 to 1.3 kΩ, and the O-ring on the insulating inner housing; rotor at 0.2 to 0.3 daN.m — the same values as the A610. Plugs: Eyquem 805 LJSP on the Z7U, gap 0.65 ± 0.05 mm (on the same table, 803 LJS for the Z6W A700 and 803 LJSP for the Z6W 702). Access: bank 1, on the right — remove the turbo's air hose; bank 2, on the left — remove the turbo's oil line; on refitting, run the leads through their grommets. Alpine M.R.273, D501 update, folios C-2a, C-10-1a and C-10-2a · Alpine M.R.297, folio 17-1.
With the XR25, engine warm, coolant at 85 ± 5 °C, reading D03 # 12 — the idle valve's duty cycle. Too high: clean the throttle body, then check the injectors and the ignition. Too low: look for an air leak or strain on the throttle cable or linkage — check that the canister bleed valve closes, the throttle body, the idle valve's connections and the potentiometer circuit. At the bottom limit, # 12 = 29%, it is the throttle linkage adjustment to check, because “too much strain on the linkage can stop the throttle closing properly”: with the air hose between turbocharger and intercooler removed, the linkage joint must not rest on the spigot, and there must be at least 5 mm of clearance at rest; that clearance comes from the rod's length, preset at 185 mm between the two joints, and at full throttle the rod end must not touch the spigot either — shorten the rod if it does. ⚠️ One setting is off limits: the air by-pass screw on the throttle body must never be altered. The valve's earth timing can also be read directly: total period 10 ms = 100%; ignition on and engine stopped, 1.8 ms (18%) on terminal 5 and 8.2 ms (82%) on terminal 3; warm engine at idle, 6.5 ms (65%) and 3.5 ms (35%). And a warning worth keeping: “even if values are displayed, that does not mean the computer is free of faults”. Alpine M.R.297, folios 17-15 and 17-16.
Rev limit: 6,100 rpm, with 6,300 rpm allowed momentarily, for 3 seconds at most; injection is re-enabled at 5,800 rpm. Air conditioning, which the computer drives: it decides from inputs 30 and 34 whether to engage the compressor through output 13 — but only once the engine has idled at least once, for a few seconds, after starting, and not before 20 seconds after start-up. About 1 second before engaging the compressor it opens the idle valve, which shows at idle as a rise from 700 to 900 rpm; it reduces the air before disengaging it. Above 115 °C coolant it will not engage the compressor, above 5,900 rpm either; and as soon as the compressor runs, the cooling fans turn at half speed. Other points from the same page: computer in the passenger compartment, in the middle behind the rear seat backrest, injection relays in its housing; NTC sensors — air on the throttle housing, coolant on a water pipe facing the fuel pressure regulator; diagnostic socket in the engine bay left of the turbocharger; the dashboard injection warning lamp does not work; and the throttle housing's bypass screw must never be adjusted. The catalysed R25 V6 Turbo's strategy is the same in outline, with its own figures: idle from 750 to 900 rpm, and the fans started at medium road speeds. Alpine M.R.297, folio 17-3 · Technical note 1558, folio 17-1.
Engine stopped, ignition on: first a visual check that the idle valve is fitted with its arrow pointing towards the manifold. Enter D03: bar graphs 1, 8, 10 and 13 lit and 108.3 on the display — 108 for the system, 3 for injection diagnosis. Engine cold: # 02 and # 03 at ambient ± 5 °C; # 01 950 to 1,025 mbar. # 17: 7 to 13 at idle, rising, 225 to 252 flat out, 128 with bar graph 3 lit in fault. Boost solenoid valve # 11, audibly clicking: 3 ± 0.5 % at idle, 99 ± 0.5 % at full load. Warm idle: # 02 80 to 100 °C once a fan has cut in; # 03 above ambient; # 04 11.5 to 14.5 V; # 06 650 to 750 rpm with no consumers; # 12 29 to 46 %; with the AC on, accelerated idle 900 ± 50 rpm, bar graph 14 right lit compressor off, both sides lit compressor on. Road test: # 18 = speedometer, hard acceleration in 2nd above 15 km/h; knock sensors, full throttle 2,000 to 4,000 rpm in 4th: # 13 variable and not zero, # 15 between 0 and 3; boost in the same conditions: # 01 ≤ 1,750 mbar, and ≤ 1,710 mbar above 3,500 rpm; then, engine stopped, ignition on, # 20 between 0 and 21 %; oxygen sensor, 50 to 80 km/h in 3rd: # 05 between 70 and 640 mV with max-min above 540 mV, # 35 between 50 and 200 — # 05 barely moving and/or # 35 = 128 means the sensor is faulty. Diagnostic socket: 2 earth · 3 centring · 6 + 12 V before ignition · 8 injection warning lamp · 9 injection information from the computer · 10 diagnostic selection — the other six pins are not connected, and the cap carries no bridge. Beside the catalysed R25 V6 Turbo, almost every figure moves: 107.3, idle 700-800 rpm, # 12 in ms, # 05 50-900 mV, # 35 20-230, boost up to 1,950 mbar, and memory-seat pins on the socket. Alpine M.R.297, folios 17-8 to 17-14 · Technical note 1558, folios 17-6 to 17-11.
It is screwed into the bend of the exhaust pipe at the turbocharger outlet, and reached by removing the inlet manifold frame. On removal, take care not to drop the nut-ring that unscrews with the sensor, then clean the thread. On refitting, coat the thread with an anti-seize compound rated for extremely high temperatures, screw the sensor in by hand, then tighten to 2.7 to 3.4 daN.m. Two rules stand out. “The sensor's wires must be neither spliced nor soldered. If one of the wires breaks, the sensor must be replaced”. And, if the idle is unstable or hunting, check with a voltmeter that the sensor's heater is receiving 12 V — an oxygen sensor's ceramic only conducts from about 250 °C. The catalysed R25 V6 Turbo's note gives the same location, the same torque, the same ban on repairing the wires and the same heater check. Alpine M.R.297, folio 17-21 · M.R.249, NT 1205 E supplement, page 18 · Technical note 1558, folio 17-18.
Engine stopped, pump driven by bridging terminals 3 and 5 of relay 236 — the one next to the computer, between the rear seat backrests — and, the manual says it twice, with the computer switched off. Pressure: tee (tool Mot. 1207) with a 0-6 bar gauge on the regulator's supply line, the regulator's vacuum hose on a hand pump: 3 ± 0.2 bar; apply about 500 mbar of vacuum and the pressure must fall by the value on the vacuum gauge; at idle, the gauge must again show 3 ± 0.2 bar reduced by the manifold vacuum. Pump pressure: clamp the tank return for a few seconds — more than 5 bar, otherwise check circuit, pump and filter. Delivery: return line into a 2,000 ml measuring glass — 130 l/h, that is one litre per half-minute, against 80 l/h on the Safrane V6. Leak test, specific to a turbo engine: apply 1 bar relative to the regulator, which simulates a manifold pressure close to maximum boost; run the engine, fuel pressure should rise by 1 bar, and check the whole system is tight. Injectors: rail and injectors removed, each injector in a 100 cm³ glass (Mot. 845), pump running — nothing must come out; then feed each injector 12 V and earth: the glasses fill, and an injector delivering noticeably less than the others is replaced. Filters: a pre-filter between tank and pump, renewed every 50,000 km like the main filter; the main filter sits by the right rear wheel and its lines cannot be clamped — have rags ready. Alpine M.R.297, folios 13-2 to 13-6.
Engine running for the pressure — where the Alpine A610's check is done engine stopped. Pull off the hose at the T-piece that feeds both injection rails, fit union Mot. 904 and gauge Mot. 843 (0 to 6 bar), start the engine and compare with the specifications chapter (2.5 ± 0.2 bar at zero vacuum on the Z7U 700). Apply 500 mbar of vacuum to the regulator: fuel pressure must drop by that value. Pump pressure: clamp the tank return for a few seconds — more than 5 bar, otherwise check the power supply, the pump and the fuel filter. Delivery: a hose on the regulator's return to the tank, into a measuring glass; run the pump by bridging terminals 3 and 5 of the pump relay connector (the thick wire), computer disconnected. Minimum 130 l/h — more than one litre in 30 seconds. If delivery is too low, check the pump's supply first: the note gives about 10 % loss for a 1-volt drop — the same rule the Safrane V6's manual prints. Technical note 1558, folios 12-1 and 13-2 · Safrane M.R.302, chapters 13 and 19.
A 12 Hz SEM solenoid valve, driven by the computer, varies the pressure seen by the wastegate by bleeding it towards the air filter inlet. The computer has the maximum boost in memory, compares it with what it measures and applies a positive or negative correction depending on engine speed, load and pressure — the value read under # 20. Above nominal it limits (negative correction); below, it corrects upwards. The valve's three hoses: (1) to the wastegate capsule, (2) to the upper part of the throttle housing, (3) to the air filter outlet — check them, and the connector, on refitting. In the circuit, calibration Aj4 Ø 1.9 ± 0.1 mm, and a 0.3 mm calibration in the line to the safety pressure switch. Boost check: foot down from 2,000 to 4,000 rpm in 4th, read the maximum under # 01 — below 1,950 mbar, and just after the peak below 1,920 mbar at 3,500-4,000 rpm, but above 1,860 mbar. Reading # 20, with caution since it varies with engine speed: the note's graph gives a band that rises with rpm, and below 4 (pressure too high) you check the Ø 1.9 mm calibration for conformity, cleanliness and burrs, then the wastegate setting; above 23 (pressure too low), the SEM valve, the hose connections, the calibration and the wastegate setting. Ignition on, engine stopped: a new or blank computer shows about 65 ms; a car short of power, 26.16 ms; boost too high, negative correction, about 0.8 ms. The bypass valve alongside stops pressure building above the throttle when it snaps shut: manifold vacuum opens it at 200 ± 20 mbar, recirculating air from turbo outlet to inlet — which also keeps the turbo spinning and shortens the response when the driver accelerates again. Technical note 1558, folios 12-6 to 12-10.
At the XR25, engine warm, coolant 85 ± 5 °C, reading D03 # 12. # 12 above the conformity maximum: clean the throttle housing, check injectors and ignition, then find the minimum correction — unscrew by-pass screw (A) until idle speed rises, then screw it back in to raise the value by 0.2 to 0.3 ms; the note's example: minimum 3.23 ms, set to 3.4 ms. # 12 below the minimum: look for an air leak or a trapped cable, then check that the canister purge valve closes, the throttle housing's conformity, the idle valve's wiring and the potentiometer circuit. Throttle cable, if # 12 sits at its minimum (3.23 ms): the throttle may not be closing fully. Through opening (1), the pin on the cable's bellcrank must not touch its bracket (2) — with the rod length right, there must be at least 3 mm between pin and bracket; preset rod length 185 mm between the two ball joints. Load potentiometer, ignition on, engine stopped, D03 # 17: idle 7 to 13 (bar graph PI lit), part load 20 to 190 (bar graph out), full load 225 to 252 (bar graph PF lit). After adjusting, switch the ignition off and on again, re-check # 17, press the pedal two or three times, and check the return to idle and the full-load value — with the pedal, never by moving the linkage from the engine bay. # 17 = 128 with bar graph 3 lit is a fault: check the potentiometer, its setting and its tightening on the throttle housing. Set beside the Alpine A610's manual, three differences: the A610 wants 5 mm of clearance rather than 3, reads # 12 in % (29 % at the bottom limit) rather than ms, and forbids touching the by-pass screw that the R25 Turbo's note has you adjust. Technical note 1558, folios 17-14 to 17-16 · Alpine M.R.297, folios 17-15, 17-16 and 17-18.
To cool the fuel going back to the tank — using the air conditioning. The manual describes a heat exchanger between fuel and refrigerant: the fuel return line is run alongside the refrigerant hoses, whose temperature is well below that of the fuel lines. It sits in the central tunnel, under a plastic housing; with the housing off you see the cooler, the fuel return line running behind the injection rails, and the low-pressure refrigerant hose of the A/C compressor. Two consequences for anyone working on it. The cooler cannot come out until the refrigerant has been drained — for that, as for refilling, the manual refers to the “Air conditioning” handbook. And on removal, the fuel still inside the cooler must not be allowed to spill; refrigerant unions are tightened to 2.8 to 3.2 daN.m on refitting. Alpine M.R.297, folio 13-8.
In three phases, because on a turbo engine the pressure at each take-off changes sign with the load. Atmospheric phase: the oil vapours are returned directly through the non-return valve and an air correction jet of Ø 1.5 mm. Low engine speed, high load: the pressure ahead of the compressor is close to atmospheric, and the vapours are returned through the vacuum capsule. High engine speed, high load: a depression forms ahead of the compressor, the vacuum capsule closes, and breathing takes place through a calibrated Ø 5.5 mm drilling. Set beside the other PRVs in the Library, the calibrations are different again: 1.7 and 6.5 mm on the Safrane's atmospheric Z7X, 2 and 8.5 mm on the Alpine V6 Turbo. Alpine M.R.297, folios 14-1 and 14-2 · Safrane M.R.302, chapter 14 · Alpine M.R.273, D501 update, folio B-54a.
Through three paths, since under boost the manifold can no longer draw the vapours in. Continuous, moderate purge through a Ø 0.5 mm jet. Direct purge through the solenoid valve, which only works when engine speed exceeds 1,000 rpm, coolant exceeds 60 °C and manifold pressure is stable and no higher than 910 mbar. And under boost, purge through a non-return valve (the Pierburg “pulsair” valve) — the solenoid valve is then out of action, since manifold pressure is above atmospheric. Three fitting rules. The tank's non-return valves vent it through the canister and stop it draining if the car overturns — so they must be fitted the right way up, “oben-top” marking upwards. The overpressure valve, set to 40-50 mbar, stops the tank pressure rising if jet Aj3 (Ø 1.5 mm) or the canister blocks; its part A is black — that identifies its setting — and part B is grey, the two arrows show the direction vapours escape if the tank is over-pressurised, and part A faces the union to the non-return valve and purge solenoid. And hoses and clamps must be correctly placed and tightened after any work. Alpine M.R.297, folios 14-3 to 14-7.
With a 0 / −1,000 mbar vacuum gauge connected at point M2 of the circuit and a voltmeter on the purge solenoid valve's terminals, engine warm — after the cooling fan has come on. At idle: very low vacuum, the reading at M2 is 0 mbar, and 0 V at the solenoid. If M2 shows the manifold vacuum instead, check the calibrated jets or the valve's connection. Blipping the throttle (moderate acceleration): the vacuum goes from 0 to −150 to −200 mbar, holds for 2 seconds and drops back to 0, with 12 V at the solenoid. If not, check the valve's pneumatic and electrical connections and the connection of the fuel vapour return lines. The circuit's jets, for reference: Aj1 Ø 1.2 mm, Aj2 Ø 0.5 mm (the continuous purge), Aj3 Ø 1.5 mm (next to the canister). And the hoses are identified by colour rings, in three columns — foolproofing, marking, function: A white / white / yellow, B orange / orange / none, C brown / brown / yellow. Alpine M.R.297, folios 14-3 and 14-8.
Like the Alpine A610's, in three ways — but not with the same thresholds. Continuous, minimal purge through a calibration: the text prints “Ø 5 mm”, and the diagram's only calibration, Aj3, is marked Ø 0.5 mm. Direct purge through the solenoid valve, only when engine speed exceeds 1,200 rpm, coolant exceeds 60 °C and manifold pressure is stable and below 900 mbar — against 1,000 rpm and 910 mbar on the A610. Under boost, through the Pierburg non-return valve, the solenoid no longer being operated: blow into its lower part (C) and the air must pass to (F); suck, and no air may pass from (F) to (C). To reach the canister or the solenoid valve, the air filter unit must come out. Diagnosis: gauge at M2 and voltmeter on the solenoid's terminals, engine warm after the first cut-out of the cooling fan. At idle: very weak vacuum, 0 mbar, 0 V — if M2 shows the manifold vacuum, check the conformity of calibration Aj3 or the solenoid's connection. Moderate acceleration: the vacuum goes from 0 to 150-200 mbar, holds about two seconds and drops back to 0, with 12 V at the solenoid; otherwise check its pneumatic and electrical connections and the vapour return hoses. The gauge range is printed two ways too: 0 / −1,000 mbar on the diagram, 0-100 mbar in the diagnosis table. The hoses carry colour rings (centring, marking, function), which the note tabulates letter by letter. Technical note 1558, folios 14-2 to 14-7 · Alpine M.R.297, folio 14-5.
No — and the difference is electrical, not dimensional, which makes it dangerous. The Safrane's Z7X 722/723 runs Bendix DEKA solenoid injectors of 14.5 ± 0.5 Ω — high impedance. Every other injected PRV in the Library runs 2.5 Ω injectors: the Renault 25 V6 Turbo (2.5 ± 0.5 Ω), the Alpine GTA V6 Turbo (2.5 ± 0.5 Ω), the A610 (2.5 ± 0.5 Ω). Nearly six times less. An injector that drops into the same rail can therefore be electrically wrong for the computer driving it, and a low-impedance injector on a high-impedance driver stage is a burnt driver stage. Same story for the throttle housing: all four cars use a Solex Ø 55 mm — but the reference is 974 (manual) or 975 (automatic) on the Safrane, against 984 on the R25 V6 Turbo and the A610. And the throttle potentiometer windows do not match either: 10 to 47 at idle and 190 to 252 at full load on the Safrane, against 7 to 13 and 225 to 252 on the other two. Safrane M.R.302, chapter 12 · Technical note 1558, folio 12-1 · Alpine M.R.297, folio 12-1 · Alpine M.R.273, D501 update, folio B-49a.
It is the answer to a problem the closed loop alone cannot solve, and the manual sets it out plainly. In closed loop, the richness regulation (# 35) alters injection duration to hold lambda 1; its correction value oscillates around 128, between 0 and 255. But components drift over the life of the car, and the correction may end up sitting near 0 or 255 just to reach lambda 1 — at which point it has almost no authority left. Self-adaptation shifts the injection map itself so that # 35 returns to oscillating around 128, and the authority comes back. It works in two halves: # 30 corrects medium and high loads, # 31 corrects low load and idle. The manual's own example is the clearest explanation of the idea: on a car with dirty injectors, the mixture is weaker for a given injection time, so # 35 oscillates around 200 to reach lambda 1 — leaving only 55 units of correction towards maximum richness. Self-adaptation then moves the map towards enrichment until # 35 comes back to 128. One instruction goes with it: # 30 and # 31 must not be read or analysed except after a customer complaint about how the engine runs. Safrane M.R.302, chapter 17.
Note the readings under gates 30 and 31, then disconnect the battery to erase the computer memory — both values go back to 128. Engine warm, coolant above 80 °C. Then stabilise the manifold pressure at five points, for at least 20 seconds each: on the Z7X, 300 → 420 → 540 → 660 → 800 mbar, each ± 20, read as a steady figure under # 01 on the XR25. Third or fourth gear, progressive acceleration, on the level, without exceeding 4,250 rpm. Then drive normally, gently and in varied conditions for 3 to 6 miles. Read gates 30 and 31 again: having started at 128, they must have moved — if not, start again and respect the conditions. The manual's analysis example: a customer complains of lack of performance and flat spots; after the test no bar graph shows a fault and richness regulation is correct (# 05 and # 35), but # 30 sits at a richness threshold. Conclusion: the system is confirming a lack of fuel, so look at fuel pressure — regulator, pump, filter — or dirty injectors. ⚠️ And a trap on the other gate: # 31 is very sensitive and hard to read. A car with # 05, # 35 and # 30 all correct but # 31 close to 0 has no idle problem at all: it may simply be a saturated fuel vapour canister bleeding partially at idle. Safrane M.R.302, chapter 17.
There are four, each answering a different accident. The ball valve stops fuel frothing back up the filler neck — and it is only fitted to cars running on unleaded. The “overturn” valve does what its name says: if the car rolls over, it stops the tank draining through the canister pipe or the vent pipe. The over/under-pressure valve opens if the vapour rebreathing circuit is blocked, to spare the tank both inflation and the opposite — “as fuel is used, the fuel tank is sucked in”. And the over-filling safety valve works on the cap: with the cap removed it is shut, trapping a pocket of air in the vent chamber so that fuel cannot fill it; put the cap back and it opens, letting the tank breathe to the canister. Add the unleaded neck's own two features — a smaller opening that a leaded nozzle will not enter, and a flap closing the neck against vapour and fuel escaping — and a tank that looks like a plain steel box turns out to hold six separate safety devices. On 4×4 cars, one more difference: the filler neck is integral with the tank. Safrane M.R.302, chapter 19.
Three checks that separate three different faults. Supply pressure: disconnect the fuel inlet pipe where it joins the engine, fit the T-piece of tool Mot. 904 and the 0-6 bar gauge of tool Mot. 843, start up and compare with the specification. Then the regulator's own test: disconnect the vacuum pipe from the regulator and, at idle, the pressure must rise by 600 to 700 mbar — that is, by the difference between atmospheric and manifold pressure. Reconnect the pipe quickly. Pump pressure: clamp the tank return pipe for a few seconds; the pressure must exceed 5 bar. If it does not, the fault is in the electrical circuit, the pump or the filter, not the regulator. Delivery: run a hose from the regulator's tank return into a measuring cylinder and drive the pump by shunting tracks 3 and 5 of the fuel pump relay connector, computer disconnected. Minimum 80 l/h — nearly 1.5 litres in 60 seconds, from a Walbro pump living in the tank. ⚠️ And the line that explains most “weak pumps” on an old car: a drop of 1 volt reduces the delivery by about 10 per cent. Before condemning a pump that tests fine on the bench, measure the voltage at its connector. Safrane M.R.302, chapters 13 and 19.
Every cover comes off first: the three bolts (A) of the upper cover, the two side cover bolts (B), then the four nuts (C) of the cover on its metal mounting; unplug the six plug leads (they can stay on the cover) and lift the assembly out towards the front left. Throttle housing: remove the flexible air intake hose (collar at the air filter, three Torx bolts at the housing), the oil vapour rebreathing pipes and the idle valve's supply pipes; unplug the air temperature sensor; remove the wiring bolt and unplug the throttle potentiometer; free the accelerator cable, its spring and, if fitted, the cruise control ball joint; then the three bolts on the intermediate manifold. Refit with a sound seal, connectors clipped home, rebreathing pipes in good order and plug leads clipped on. Injection rails: the front rail feeds cylinders 1, 2, 3, the rear rail 4, 5, 6; the fuel pressure regulator takes its manifold pressure from the intermediate manifold, and — the manual's note — there is no link between the pulse damper and the regulator. Remove the wiring channel's four bolts and the five hook bolts, the rebreathing pipe assembly and the idle valve supply, disconnect the fuel inlet and return at the rear right of the cylinder head, remove the rails' four bolts and unplug the injectors, then the regulator–pulse damper bolts and its vacuum pipe; the rails, regulator and damper come out together. Two warnings in a box: under every rail and regulator mounting sits a thermal insulation block — keep them; and the fuel unions on the rails and regulator are rigid and cannot be removed. Intake manifold: unplug the air temperature sensor and idle valve; on the engine lifting bracket, the wiring bolt and the throttle potentiometer; remove the four bolts of the bracket between the right engine mounting and the manifold, the cruise control vacuum pipes and the canister pipes crossing it; unhook the accelerator cable; remove the four manifold bolts; move the leads forward and take the manifold–throttle housing assembly out to the left. On refitting, renew every seal removed, tighten the manifold to 1.5 +0.5/−0 daN.m, and check the insulation blocks are back under every rail mounting. Safrane M.R.302, chapters 12 and 13.
The pump — a Walbro, 80 l/h at 12 V and 3 bar — sits in the tank, and access depends on the transmission. 4×2: through the access hole in the boot, cover removed; disconnect the battery and the pump connector, remove the collars on the fuel inlet and return, loosen the mounting nut with tool Mot. 1242, and lift the pump assembly out. 4×4: the spare wheel has to come out to reach it, and the pump cannot be removed through the boot hole — the whole tank must come out; the electrical supply and the two fuel pipes are disconnected through the boot hole first, then the pump nut is undone with Mot. 1242 once the tank is out. The warning that goes with it, boxed: put the nut back on the tank immediately after removing the pump — after a few minutes it will no longer go on, because the hole swells from the petrol around it, and the tank must then be replaced. On refitting, the pump seal goes on first (renewed if damaged); line the pump up with the arrows on pump and tank; the lower part of the pump touches the bottom of the tank, so hold it down while tightening the nut to 5 daN.m maximum. No smoking and no heat source anywhere near. The fuel filter: clamp the inlet and outlet hoses with Mot. 453-01 first. 4×2 — two bolts G; on refitting, respect the arrow on the filter body and tighten the bolts until the filter no longer turns, 0.4 daN.m. 4×4 — the filter is held by two collars; same arrow, collars correctly positioned against mounting and filter. Safrane M.R.302, chapter 13.
Draining (petrol): a flexible pipe on the fuel pump outlet through the boot access hole, long enough to reach a container; open the computer's protective cover, disconnect the fuel pump relay (the one with Ø 5 mm wires) and bridge tracks 3 and 5 — the pump runs. Let it pump until fuel comes out intermittently, and no longer than a minute in those conditions; remove the bridge, refit the relay, disconnect the battery. Diesels have no electric pump and need a hand pump. No smoking, no heat source. Removal — the chapter gives two procedures, illustrated with the two tanks that the fuel chapter labels 4×2 and 4×4. First (the rear axle comes down): in the boot, under the carpet, disconnect the sender and pump wiring and the pump's fuel lines; underneath, the filler neck pipes; loosen the filter strap and remove the filter and its two pipes; on the handbrake cable guide, measure distance X before moving anything, free the left cable (carefully remove its plastic stop) and the guide; in the rear left wheel arch, unclip the two brake pipes and the two controlled-suspension connectors; remove the tank strap and the four bolts of the handbrake cable guide. Jack under the rear axle assembly, taking its weight — with electronically controlled suspension, disconnect the position sensor links; remove the four axle-to-body bolts and, supporting the tank, lower the axle about 60 mm: the tank tips forward; unhook the vapour pipe; some fuel may still be inside. On refitting: new vapour pipe, new fuel pipes and new fuel filter; axle refitted on its centring dowels (9.5 daN.m); brake lines back; handbrake guide reset to distance X, counter nut tight; cable under the tank strap, then the strap (3.5 daN.m); renew damaged collars at the filler neck (3.5 daN.m on the body). Second (the tank is lowered on a jack): drain it, disconnect the fuel pipe at the filter underneath; remove the plastic filler neck cover in the rear right wheel arch (5 bolts and a panel nut); in the boot, the return pipe on the pump and the connectors; at the flap, the rubber round the filler neck; the vapour pipe at the bottom of the neck; jack under the tank, remove the strap bolts (bumper side) and lower it. This tank carries an anti-leak non-return valve for rollover, overpressure or underpressure; on refitting, both centring dowels under the body must engage, straps at 3.5 daN.m, collars and connectors checked. Safrane M.R.302, chapters 13 and 19.
Two jets and a solenoid valve, on the intermediate manifold upstream of the throttle housing. Engine stopped: the tank breathes through the canister, whose active carbon holds the vapours. At idle: the solenoid valve is not energised, but the canister is still partly bled through jet A1, Ø 0.3 mm. Above idle: at certain engine speeds and predetermined loads, the injection computer energises the solenoid valve and the canister is bled through jet A2, Ø 1.9 mm. The XR25 shows it: bar graph 16 right lights when the computer feeds the solenoid valve. Where things are: under the photo of the solenoid valve, the caption places the part on the front right wheel arch — its wording says “the canister” — with the injection computer to remove to reach it; the canister at the front, under the right side member cover, on a support held by three bolts; the vapour take-off from the tank on the upper part of the filler neck. Removal: car on a lift; from underneath, remove the four bolts of the plastic protective cover and tip it back; remove the three canister mounting bolts, lower the assembly and disconnect its pipes; release the strap and remove the canister. On refitting, make sure the vapour pipes go back on the right spigots. Beside the other V6s: the Alpine A610 and the R25 V6 Turbo purge through three paths — a continuous bleed, the solenoid valve, and a Pierburg non-return valve under boost; the atmospheric Safrane V6 has no boost to deal with, and only these two jets. Safrane M.R.302, chapters 14 and 17 · Alpine M.R.297, folio 14-5.
Two gates, and neither means what a beginner assumes. # 05 gives the voltage the sensor sends the computer, from 0 to 1,000 mV. With the loop closed, it must oscillate rapidly between 200 ± 100 mV — lean — and 700 ± 50 mV — rich, and back again; the manual notes the swing is generally at least 600 mV. A voltage that sits still, anywhere, is a sensor that has stopped working, whatever value it sits at. # 35 gives the richness correction the computer is applying, not the mixture itself: maximum 255, minimum 0, normally oscillating around 128. And the reading is the opposite of what the numbers suggest — below 128 means the computer is asking for a weaker mixture (it is finding the mixture rich), above 128 means it is asking for a richer one (it is finding it lean). So a # 35 stuck at 200 does not mean the engine is running rich: it means the computer is fighting to enrich a mixture that is too lean. Safrane M.R.302, chapter 17.
Engine cold, ignition on: coolant and air temperature both at ambient ± 5 °C — two sensors reading the same thing is the quickest proof they are both alive; absolute pressure according to local atmospheric pressure, 950 < X < 1,025 mb; throttle potentiometer 10 < X < 47 with no load and 190 < X < 252 at full load. Engine warm at idle: coolant 85 to 95 °C, air above ambient, battery 11 to 13 V, idle 650 to 750 rpm with the valve's duty cycle at 26 to 36%, 750 ± 50 rpm with an automatic in drive and 900 ± 50 rpm with the air conditioning on. ⚠️ And the reading that matters most is the one that looks normal: a potentiometer showing exactly 128, or a pressure sensor showing exactly 103 mb, is the computer's fault value — the substitute it runs on once it has given up on that sensor. Neither figure is a measurement. Last instruction, and it saves time: the throttle potentiometer cannot be adjusted; when one is replaced you check the values read under # 17, nothing else. The Alpine A610 shows the same fault value — 128 under # 17, with the line 3 bar graph lit — and its manual adds two measuring precautions: use the accelerator pedal, not the throttle linkage under the bonnet, to read the idle and full-load values, and press the pedal two or three times before reading them. It does, on the other hand, describe an adjustment of the potentiometer, followed by switching the ignition off and on again. Safrane M.R.302, chapter 17 · Alpine M.R.297, folio 17-18.
Rev limit, before injection cut-off: Z7X — 6,300 rpm in 1st and 2nd, 6,200 rpm in 3rd, 4th and 5th; J7R and 12-valve J7T 6,350 rpm; J7R and 8-valve J7T 6,000 rpm. The Alpine A610's Z7X stops at 6,100. Warning lamp: on the Safrane it is used — unlike the A610 and the catalysed R25 V6 Turbo, whose lamps are not connected — and, depending on the seriousness of the fault, a voice synthesiser message may go with it (if fitted). It lights for a faulty absolute pressure sensor, throttle potentiometer, oxygen sensor, vehicle speed sensor, idle regulation valve, primary ignition circuit, injectors, or TDC sensor connections reversed. And with the electronic anti-theft: if the decoder's signals to the computer are interrupted while running, between idle and 1,800 rpm the lamp flashes, with a voice message. Vehicle speed: an impulse generator in the speedometer cable, under the dashboard at brake pedal level, on the right — wire A + after ignition (after fuse), B speed information, C earth; the signal reaches computer track 3. The manual's warning: no speed information can explain an idle regulation that misbehaves — road test with the XR25, # 18 must match the speedometer, and right-hand bar graph 9 must stay out. One more practical rule: erasing the computer memory cancels the auto-corrections, so drive the car about 5 minutes before handing it back to the customer. Safrane M.R.302, chapter 17 · Alpine M.R.297, folio 17-3.
With cassette no. 10 and diagnostic fiche no. 13; the diagnostic socket is in the engine compartment, in the same place on every petrol version. Enter D03 (selector on S6): the display reads 4.INJ. What changes from earlier injection systems is the identification: it is no longer a diagnostic code but the computer's part number, read directly — enter G70* and it appears in three sections, each shown for about 2 seconds, the sequence repeated twice. The manual's example, a B544 with the Z7X 722 engine (4×2): 77 00 / 860 / 292. The Renault 25 V6 Turbo still works the old way: after D03 its display shows 107.3 — 107 for the system, 3 for injection diagnosis. Erasing the memory after work on the injection: G0**, selector on S6 — the fiche adds “if selector on P or N” — and this erases nothing belonging to any other system on the car. Cassette no. 10 also opens three new readings: # 21 idle RCO auto-correction, # 30 and # 31 richness auto-correction under high and low loads. The other readings and their units: # 01 mbar, # 02 and # 03 °C, # 04 V, # 05 mV, # 06 rpm, # 11 turbo pressure RCO %, # 12 idle valve RCO, # 13 pinking signal, # 14 speed variation rpm, # 15 pinking correction in degrees, # 16 atmospheric pressure mbar, # 17 throttle potentiometer, # 18 km/h, # 20 turbo pressure correction, # 35 richness correction. Safrane M.R.302, chapter 17 · Technical note 1558, folios 17-7 and 17-9.
They are the answers to the additional tests — star codes that extend a bar graph's fault finding. The manual lists *02, *04, *05, *06, *07, *08 and *24, and the fiche prints each one beside its circuit: *02 the computer–ignition power module link, *04 the fuel pump relay, *05 the idle regulation valve circuit, *06 the EGR circuit, *07 the WG circuit, *08 the oxygen sensor / CO potentiometer circuit, *24 the injector circuit. Enter, for example, *02, and the XR25 displays one of three words. “bon”: no fault on the element or line. “CO”: open circuit, the line is cut. “CC”: short circuit — find it with the MS 1048 test board, checking insulation against + 12 V, earth, or between two wires. Two more displays mark a definite fault: “CO.0”, a short to earth or an open circuit; “CC.1”, a short to battery +. The test that follows: battery disconnected, ohmmeter, continuity and insulation against earth and battery +, with MS 1048 plugged in in place of the computer's 35-way connector. The Renault 25 V6 Turbo uses the same abbreviations on its bar graphs (CC short circuit, CO open circuit) and the same 35-contact MS 1048 board — with a warning its note prints plainly: wrong connections can destroy some or all of the injection components, and nothing done outside the XR25 — bridging terminals, ohmmeter or voltmeter checks — may be done with the computer connected. Safrane M.R.302, chapter 17 · Technical note 1558, folios 17-5 and 17-12.
Twenty lines, left and right. 1 — left: computer self-test, lit = computer faulty; right: code present, lit ignition on and engine running. 2 — left: link between computer and ignition power module (ignition pulses); right: line between the anti-theft decoder and the computer. 3 — left: flywheel sensor connections reversed; right: TDC detection fault — sensor, its circuit, or a target problem (cycle irregularity). 4 — left: fuel pump relay, not used; right: injector circuit, short or open. 5 — left: idle regulation valve circuit; right: air temperature circuit (check # 03). 6 — left: EGR, not used; right: coolant temperature circuit (# 02). 7 — not used. 8 — left: oxygen sensor circuit, with # 05 fixed and # 35 = 128; right: absolute pressure sensor circuit (# 01). 9 — left: line between automatic gearbox and injection computers; right: vehicle speed circuit, possibly with no speed on the instrument panel (# 18 on a road test). 10 — left: throttle potentiometer circuit (# 17); right: pinking sensor circuit (# 13 and # 15 under acceleration). 11 — throttle potentiometer recognition: left full load, right no load. 12 — left: lit with the automatic's lever on P or N, out in Drive; right: torque reduction requested during gear changes (ignition retard). 13 — anti-theft active, the car cannot be started. 14 — left: flywheel signal, lit ignition on, out as soon as the starter turns and while the engine runs — if it stays lit, see right-hand bar graph 3; right: EGR, not used. 15 — left: pump active (the computer earthing the pump relay): lit 3 seconds at ignition on, then out, and lit again on the starter and with the engine running; right: WG, not used. 16 — left: idle regulation requested; right: canister bleed active, solenoid valve fed (Z7X engine). 17 — air conditioning activated: press Auto then AC at 18 °C to confirm the request. 18 — left: compressor request; right: authorisation from the injection computer, depending on engine conditions. 19 — electric windscreen de-icer selected (the fiche says to switch the AC off for this check). 20 — XR25 memory: enter “0” to store values and bar graphs. Safrane M.R.302, chapter 17.
Three checks. Vehicle speed — car moving, bar graph 9: # 18 = the speed on the speedometer. Pinking sensors — full load from 2,000 to 4,000 rpm in 4th, bar graph 10: # 13 variable and not zero, # 15 ≤ 6. In fault, right-hand bar graph 10 lit, # 13 = 0 and # 15 = 0 — and the footnote that explains the lost performance: in fault mode the ignition advance is retarded by 2 degrees, which # 15 does not show. Oxygen sensor — 50 to 80 km/h in 3rd at a steady speed, bar graph 8: # 05 varies between about 50 and 900 mV, # 35 varies around 128, between 0 and 255. In fault, left-hand bar graph 8 lit, # 05 barely moves, # 35 = 128. The Renault 25 V6 Turbo's road test, under the same conditions, is stricter on two readings and adds a third: # 15 below 3; # 05 between 50 and 900 mV but with maximum minus minimum above 540 mV, and # 35 between 20 and 230; and a boost line — at full load in 4th from 2,000 to 4,000 rpm, # 01 ≤ 1,950 mbar, 1,860 to 1,920 mbar above 3,500 rpm, # 20 between 4 and 23. On the R25 Turbo, a # 05 that barely moves and/or # 35 = 128 means, in the note's words, oxygen sensor defective. Safrane M.R.302, chapter 17 · Technical note 1558, folio 17-11.
Last, and only after three checks. First: bar graph 5 out (idle valve circuit), bar graph 11 showing no load recognised, and bar graph 16 lit (regulation requested by the computer). Only if all three are right may # 12 and # 21 be used. # 12 is the idle valve's RCO; the conformity values are nominal, and outside them an anomaly may be suspected. # 21 is its auto-correction, which the manual calls “an automatically adjusting bypass”: it follows slow changes in the engine's air requirement (running-in, a dirty engine…) to bring the RCO back to a nominal average, and it moves between two thresholds. Its reading is only meaningful if idle is outside tolerance and # 12 is outside its range. Engine warm, the table gives: Z7X — 26 ≤ # 12 ≤ 36 %, −3.1 ≤ # 21 ≤ 6.2 %; J7R–J7T 8-valve — 26 to 38 %, −2.3 to 3.9 %; J7R–J7T 12-valve — 25 to 32 % (23 to 30 % on the J7T 761), −8.6 to 6.2 %. The two worked examples use the 8-valve four-cylinder's thresholds. Idle too high, # 12 = 25 % and # 21 = −2.3 %, correction at its minimum: an air leak, or a throttle housing stop incorrectly set. Idle too low, # 12 = 39 % and # 21 at its maximum threshold (the text prints “−3.9 %”, the table gives +3.9 % for that engine): the engine is dirty. In that case only: engine stopped, disconnect the battery to erase the computer memory, start, and unscrew the bypass gradually to bring the RCO to the middle of its conformity range — the manual adds “if 28 ≤ RCO ≤ 36 %, adjust to 32 % with the bypass screw”, without naming the engine. And a note: on the new throttle housing, the bypass screw is fully tightened. Safrane M.R.302, chapter 17.
The note gives two tables. Engine stopped, ignition on: first a visual check that the idle regulation valve is fitted the right way — flow towards the intake manifold, in the direction of the arrow on top of the valve. Enter D03: bar graphs 1 (signal present), 8 (TDC code), 10 (idle switch) and 13 (oxygen sensor present) lit, and 107.3 on the display. Engine cold: # 02 and # 03 at ambient ± 5 °C; # 01 according to barometric pressure, 950 to 1,050 mbar. Load potentiometer # 17: 7 to 13 at idle, rising at part load, 225 to 252 at full load. Boost solenoid valve # 11 (opening ratio), with the valve audible: 2.28 at idle, 83.38 at full load. Engine warm at idle: # 02 80 to 100 °C after the first cut-out of the cooling fan; # 03 above ambient; # 04 11.5 to 14.5 V; # 06 700 to 800 rpm with no electrical consumers, and # 12, the idle valve's opening ratio, 3.23 to 3.7; # 01 350 to 450 mbar. Air conditioning switched on: bar graph 14 right lit with the compressor off, both sides lit with it on, and idle raised to 950 ± 100 rpm. Power steering pressure switch — steering turned, AC off: bar graph 14 left lit, idle 900 ± 100 rpm. Set beside the Safrane's table, three readings differ: pressure 950-1,050 against 950-1,025 mbar, coolant 80-100 against 85-95 °C, battery 11.5-14.5 against 11-13 V. Technical note 1558, folios 17-9 and 17-10 · Safrane M.R.302, chapter 17.
Layout — Bendix multipoint injection on the Z7U 700, one computer for injection and ignition, with ignition correction from a pinking sensor on the cylinder head, under the fuel pressure regulator. The computer sits front left in the engine compartment, in a plastic housing next to the canister, with the injection relays; the air temperature sensor is on the throttle housing, the coolant sensor on the right at the water pump; the diagnostic socket is in the engine compartment, left of the scuttle. The computer stores intermittent faults — and the injection warning lamp is not connected: there is no bridge in the socket's cap, hence no link between computer and dashboard lamp. Diagnostic socket: 1 free · 2 earth · 3 centring · 4 not connected · 5 variable power steering information · 6 + 12 V permanent · 7 free · 8 injection warning lamp · 9 “injection” information from the computer · 10 “diagnostic” selection · 11 memory seats information · 12 memory seats diagnostic selection. Depending on equipment (AC or power steering pressure switch, on terminal 34), two green relay-shaped diode housings sit near the manifold pressure sensor. Air conditioning: the computer switches the compressor (terminal 13) from inputs 30 and 34 — but only once the engine has run on idle regulation for a few seconds, and not before about 20 seconds after starting; it opens the idle valve about 1 second before engaging the compressor (and reduces the air before disengaging it), idle going from 750 to 900 rpm; above 115 °C coolant, no compressor; and the cooling fan starts systematically at medium road speeds after the AC request. Bar graphs: 1 always lit, engine stopped or running; 2 always out; 3 right lit with # 17 = 128 — potentiometer fault; 4 and 5 right lit — short circuit, left lit — open circuit; 7 right — manifold pressure sensor fault; 8 goes out on the starter, left lit — connection reversed; 11 — speed pulse sensor fault; 12 right — pinking sensor; 13 right — oxygen sensor; 14 with AC on — right lit compressor off, both lit compressor on, and with AC off the left side shows the power steering pressure switch working; 15 right — vehicle speed sensor, with # 18 = 0. # 35 reads the mixture correction around 128 (0 to 255, above 128 enriching); 128 is also the value the computer falls back on when the oxygen sensor fails. Technical note 1558, folios 17-1, 17-2, 17-4, 17-6, 17-8 and 17-12.
Because the two do not close the loop in the same way, and on one of them the loop is open at idle. On the Z7X, once the coolant reaches 45 °C the loop closes and — the manual italicises the point — stays closed until the accelerator is pressed: “the system is not open at idle speed”. You can therefore watch the sensor work at idle. On the J7R and J7T the strategy is quite different: from 45 °C the loop stays closed until the coolant reaches 80 °C, while the computer samples the corrections and works out an average; then it opens the loop after 30 seconds and holds that average, recloses two minutes later for 30 seconds, and repeats — until the accelerator is touched. Watch the sensor at idle on one of those and you will spend most of your time looking at a frozen average. Which is why the manual says, for those engines only, that the sensor must be checked warm at 1,500 to 2,000 rpm. Two cars from the same range, two ways of being right. Safrane M.R.302, chapter 17.
No, and it is a trap. On the K-Jetronic R25 V6, the water sensor feeding the idle-regulation computer is an NTC — its resistance falls as temperature rises: 8,500 to 11,500 Ω at 20 °C, 3,570 to 4,830 Ω at 40 °C, 1,700 to 2,300 Ω at 60 °C, 770 to 1,320 Ω at 80 °C (measured after 10 minutes' stabilisation, sensor left in place, between the orange wires of the 6-way connector). On the catalysed R25 V6 Turbo, both injection sensors are on the contrary positive temperature coefficient (PTC) — resistance rises with temperature: coolant 283 to 297 Ω at 20 °C, 383 to 397 Ω at 80 °C, 403 to 417 Ω at 90 °C; intake air 254 to 266 Ω at 0 °C, 283 to 297 Ω at 20 °C, 315 to 329 Ω at 40 °C. Same model of car, two opposite laws and two orders of magnitude: a workshop applying “as usual, it drops when it warms up” condemns a healthy sensor. ⚠️ And on the label, the Turbo's manual contradicts itself: its check page (folio 17-17) is headed “POSITIVE temperature coefficient (PTC)” and does give that rising table, while its specifications page (folio 12-2) writes “Bendix: NTC type” for the very same two sensors. The values are what count, because they can be checked with an ohmmeter — the label cannot. And the Alpine A610 settles the question: its manual does give a table, and it is a textbook NTC — coolant 3,050 to 4,050 Ω at 20 °C, 300 to 370 Ω at 80 °C, 210 to 270 Ω at 90 °C; air 7,450 to 12,000 Ω at 0 °C, 3,050 to 4,050 Ω at 20 °C, 1,300 to 1,650 Ω at 40 °C. A genuine Bendix NTC therefore loses a factor of ten between 20 and 90 °C. The Safrane gives exactly the same curve (coolant 3,060 to 4,045 Ω at 20 °C, 300 to 370 at 80 °C, 210 to 270 at 90 °C; air 7,470 to 11,970 Ω at 0 °C). The count, once the R25 Turbo's note is read in full: its injection overview (folio 17-1) also states that both sensors are “PTC (positive temperature coefficient)” — so the note says PTC twice, once with its rising table, and NTC once; the A610 and Safrane manuals, for their part, describe an NTC that collapses. Which one is right, no document settles; what is certain is that the label cannot be trusted and the sensor must be measured at two temperatures to see which way it works before condemning it. What matters in the workshop: 283 Ω on one car, 3,050 Ω on another and 8,500 Ω on the third, at the same temperature. Never transpose a sensor value from one version to another. M.R.249, NT 1205 E supplement, page 41 · Technical note 1558, folios 12-2, 17-1 and 17-17 · Alpine M.R.297, folios 12-2 and 17-17 · Safrane M.R.302, chapter 17.
Distributor turning clockwise, firing order 1-6-3-5-2-4, two 0.5 ohm resistors (1.0 ohm total). Timing 13° ± 2 BTDC at 775 ± 50 rpm. Centrifugal advance: 1,000 rpm = 0° · 2,000 = 10° · 3,000 = 14° · 4,000 = 20°. Vacuum advance: 5 in Hg = 3° · 10 = 12° · 15 = 20°. Pick-up coil 895 to 1,275 ohms, trigger/stator air gap 0.25 mm — with a non-magnetic feeler gauge. Coil: primary 0.95 to 1.4 ohm at 20 °C, secondary 5.5 to 8.5 kΩ, average primary current at idle 3.2 A. Plugs Bosch HR6 DS, gap 0.6 to 0.7 mm, torque 17 to 20 N·m. ⚠️ The ignition being electronic, dwell angle can neither be read nor adjusted — only the HT curve can be examined on a scope. DeLorean workshop manual, folio M:01:04.
Three, and the third explains the first two. Never disconnect an HT wire with the engine running. Any HT wire disconnected for checking must be earthed before the engine is started. And the reason: “when the engine is running dangerously high voltages which may prove fatal are present in this circuit”. A method on the same folio avoids touching it needlessly: to prove the distributor is at fault, disconnect its connector, insert two wires from a TDC pick-up into the sockets on the electronic unit side, and move a magnet smartly towards and away — if a spark jumps between coil and HT lead, the distributor must be replaced. DeLorean workshop manual, folio M:01:04.
They cut in at about 97 °C (207 °F) and stop when the temperature falls below 91 °C (196 °F). The training manual adds a detail that prevents a false diagnosis: “the fans will remain on continuously if the coolant temperature does not drop below 91 °C” — fans that never stop are therefore not necessarily faulty. In the same chapter, for the alternator: a correctly tensioned belt deflects 6 to 10 mm, and output is checked at about 3,000 rpm under an 80 amp load, accessories and lights off for the regulated voltage. DeLorean training manual, engine chapter, pages 30 and 31.
The oxygen sensor only delivers a signal above a minimum operating temperature of about 300 °C: before that, no control at all. And the ECU deliberately sets it aside in two cases — coolant below 15 °C and wide open throttle — where the mixture is then held at a fixed value. The cold information comes from a thermistor on the coolant distribution pipe; the associated thermal switch is tightened to 40 N·m, its contact opens at 15 ± 3 °C and closes again at most 5 °C below its opening temperature. Wide open throttle is seen by a throttle micro-switch that only operates over the final 1.5 mm of travel. DeLorean training manual, emission controls chapter, pages 8, 10, 13 and 16.
Through a frequency valve — the only electrical part of the fuel circuit. Mounted on the right valve cover, it links the fuel distributor's lower chambers to the return line and opens and closes 70 times a second. When it opens, lower chamber pressure falls, the distributor's diaphragms deflect further, and more fuel goes to the injectors: the mixture richens. So the Lambda ECU does not command a quantity, it commands a pulse ratio — open time against closed time within one cycle. A ratio of 80/20 means the valve is open 80 percent of the time. The manual sums the loop up as an “action circle”: lean mixture → high oxygen → low sensor voltage → longer opening → lower pressure → more fuel → rich mixture, and round again. DeLorean workshop manual, fuel and emission section, folios D:04:07 to D:04:10.
By connecting a dwell meter to the diagnostic plug, wired to ECU terminal 17, set to six cylinders. The manual gives five cases, a complete troubleshooting method in itself. Normal operation, sensor connected and CO correctly set: 35 to 45°, reading pulsating — it is the pulsation, more than the figure, that proves the loop is alive. Oxygen sensor disconnected: 40 to 50°, steady. Sensor lead grounded: 87° minimum, steady. 1.5 volts applied to the lead: 20° maximum, steady. Full throttle or cold engine (below 15 °C): 50 to 60°, steady. A reading outside specification with the sensor connected does not condemn the ECU: “it could be caused by a rich or lean CO adjustment”. DeLorean workshop manual, fuel and emission section, folios D:04:14 and D:04:15.
With a measurement anyone can make: the length of the spark. Crank the engine and watch the arc between the coil's high tension lead and earth: more than 12 mm, the ignition is sound and you move to the fuel side; less than 12 mm or no spark, you stay in the ignition. The rest of the chart is read with a voltmeter, battery above 11 volts, ignition on: at coil terminal 15, 0 V = a broken ballast resistor or an open from the main relay; less than 6 V = a short in the primary; 6 to 8 V = normal; 12 V = a bad earth. At terminal 1: 0 V = an open primary or a module not conducting; 0.5 to 2 V = the power transistor is fine; 12 V = the module is not conducting. Then the coil secondary on an ohmmeter, 5.5 to 8 kΩ. DeLorean training manual, adjustments, tests and diagnosis chapter, C1.
With an AC measurement, engine cranking: “connect a voltmeter between pins 7 and 31d of the ignition ECU module. At cranking speed (100 rpm), a minimum reading of 1.0 volt AC should be obtained” — proof that the distributor's inductive pick-up is producing strong enough pulses. If the voltage is absent or low, check the pick-up's screened cable first, then the pick-up itself on an ohmmeter: 895 to 1285 ohms. Finally the air gap between rotor and stator: 0.25 mm, and the manual specifies the gauge — non-magnetic, because a steel feeler would cling to the permanent magnet and falsify everything. A further check on the dwell meter: 45° ± 5° depending on engine speed; a needle pinned to the end of the scale means the module no longer reacts to the pulses. DeLorean training manual, adjustments, tests and diagnosis chapter, C1.
By pushing it down by hand with the pump running — and by telling two resistances apart. The manual: “bypass the RPM relay, then depress the sensor plate and release it quickly: the plate should return at once”. And the warning that goes with it, in two parts. First safety: “the injectors spray when the plate is depressed, so use caution not to flood the engine”. Then the diagnostic trap: “the control pressure will offer some resistance when the plate is depressed. Do not confuse this resistance with seizure”. The check before it is simpler still: watch whether the plate deflects while the starter turns; if it barely moves, it is either an air leak in the intake — hoses, idle bypass pipe, manifold connection — or a plate that really is stuck. DeLorean training manual, adjustments, tests and diagnosis chapter, C2.
By removing it into a vessel, with coolant below 35 °C, and cranking: it must spray for 0 to 7.5 seconds depending on temperature — 7.5 seconds at -20 °C, falling to zero at 35 °C. The precaution not to miss is one sentence: “if the engine was previously cranked, let it sit for 10 minutes to allow the thermo-time switch heating element to cool before proceeding” — otherwise the valve will not open and a healthy part gets condemned. If it does not work: look for voltage at the valve while cranking, then an open between valve and thermo-time switch, then replace one or the other. And if it leaks, the symptom is the opposite: a flooded engine, wet plugs, impossible hot starting. DeLorean training manual, adjustments, tests and diagnosis chapter, C2.
With a 4 mm Allen key, through the access hole between the fuel distributor and the air flow sensor, engine running: clockwise richens, anticlockwise leans, target 1.0% ± 0.3. One habit to acquire: “after each adjustment the wrench must be removed and the access hole covered, to prevent a lean condition during the CO reading” — the hole is an air leak. But the real work comes first: the manual insists on checking four things, because mixture is almost never the true culprit. One, that the measuring procedure was properly followed. Two, an intake manifold leak. Three, a vacuum hose or crankcase leak. Four, the injection troubleshooting chart — control pressure, a leaking cold start valve… This adjustment is factory-sealed: it is reopened as a last resort, not as a first move. DeLorean training manual, adjustments, tests and diagnosis chapter, A3.
The Library's two documents disagree, and the difference changes the reading. The training manual, in its Lambda system test, says: “set the dwell meter to the four (4) cylinder scale” — and it is that procedure which gives the reference figures (40-50° sensor disconnected, 87° minimum with the lead earthed, 20° maximum under 1.5 V, 35-45° in operation). The workshop manual, in its CO adjustment procedure, says the opposite: “switch dwell operation for a 6 cylinder engine”, while quoting the same ranges afterwards. In practice: keep the scale of the procedure you are following, and distrust any figure quoted without its scale. The right reflex remains the manual's own: with the sensor connected, it is the needle's fluctuation, not the number, that proves the control loop is alive. DeLorean training manual, adjustments, tests and diagnosis chapter, B1; DeLorean workshop manual, fuel section, folios D:04:01 and D:04:15.
With a two-step test, engine hot: read the speed — it must be 775 rpm ± 50 — then disconnect the wire from the idle microswitch: “the rpm should increase”. If it does not move, the system is not working. The manual then gives a list of thirteen causes that is a troubleshooting guide in itself: a blown no. 1 fuse · a restricted air filter · no rpm pulse from coil terminal 1 · the manifold's idle screw not fully closed · an air leak at the bypass pipe · a shorted or open regulator · an open thermistor, which gives a permanent fast idle · a misadjusted microswitch · throttle plates not fully closed · an open diode (no control at all) or a shorted diode, which can destroy the ECU through voltage feedback from the advance cut-off solenoid · a faulty module · or, last, a fault in the injection or Lambda system. DeLorean training manual, adjustments, tests and diagnosis chapter, B2.
Yes, and it is the first box of the Lambda chart: with the RPM relay bridged (terminals 30 and 87b), listen. Four cases. The valve buzzes and the dwell sits in the 40-50° band: it is good. It buzzes but the dwell deviates: the dwell meter is wrongly connected — check the hook-up. It buzzes with no reading at all: an open or short between ECU terminal 17 and the diagnostic plug. It does not buzz and the dwell deviates or reads 0°: measure its winding resistance, 2 to 3 ohms; if that is good, suspect the Lambda harness, and if the harness is good, the ECU. A 70 hertz buzz is a diagnosis in itself — and its absence, the easiest fault in the circuit to hear. DeLorean training manual, adjustments, tests and diagnosis chapter, C3.
Because an RPM relay stops it, and that is a safety feature, not a fault. The relay receives the ignition pulses from coil terminal 1: while the engine turns it stays closed and feeds the pump and the control pressure regulator; “if the pulses stop because the engine has stopped turning, the relay opens about one second after the last pulse. This safety circuit prevents the fuel pump from pumping when the ignition switch is on but the engine is not running” — useful with a torn hose. The workshop consequence: to check pressures with the engine stopped, remove the relay and bridge terminals 30 and 87 in the connector (and 30 and 87b to power the Lambda circuit). The relay lives in the relay compartment behind the passenger seat. DeLorean workshop manual, fuel and emission section, folios D:01:15, D:02:02 and D:04:14.
A switch that provides the fuel pump's earth and opens on impact: “in the case of an accident where high impact is involved, the inertia switch will open the circuit between the fuel pump and ground. This will prevent the fuel pump from pumping fuel out of a possible ruptured hose. The inertia switch also activates the door lock circuit to unlock the doors upon high impact”. It sits under the left side of the dash panel, on the footwell wall, next to the luggage compartment release. The detail that saves a callout: “when the button is in the up position the switch is open: the fuel pump will not operate and the door locks move to unlock. To reset it, depress the button”. A DeLorean that will not start after a kerb strike may need nothing more than that button pushed down. DeLorean workshop manual, fuel and emission section, folios D:01:15 and D:01:16.
No, and that peculiarity has consequences: “the closed crankcase system does not have an air inlet for air circulation within the crankcase. This system applies manifold vacuum to the crankcase which is completely sealed to outside air”. Vapours leave through the left valve cover and the oil filler cap, into the cold start valve's air tube, where a metered orifice doses the vacuum applied. Hence two faults that look different but share one cause: a plugged orifice or hose → “excessive pressure build up within the crankcase resulting in possible oil seal and/or gasket damage”; an air leak at the crankcase → “a lean running condition, since the crankcase is connected to the intake manifold”, and the manual names the culprits: the dipstick not fully installed, an oil filler cap not sealing, tired gaskets. So an unexplained lean idle starts with the dipstick. DeLorean workshop manual, fuel and emission section, folios D:06:02 and D:06:03.
Yes: “due to the design of the fuel injection system, it will be normal to have a slight amount of pressure in the fuel tank. This pressure will be noticed when removing the fuel filler cap”. The system is fully sealed and vapours are stored in a charcoal canister in the left rear body section, purged as soon as the throttle plates open, into the cold start valve's air tube. The manual does flag the opposite fault, rarer and worse: “a restricted vapour hose between the tank and the canister will cause a vacuum to be created in the fuel tank and possible collapse of tank” — a moulded plastic tank caving in. The canister itself is not serviceable and is replaced complete. DeLorean workshop manual, fuel and emission section, folios D:01:16, D:06:01 and D:06:02.
No: “engine idle speed is not adjustable. Speed is electronically controlled to 775 rpm ± 50”. A Bosch rotary valve regulator on the left of the manifold passes the air that bypasses the throttle plates; a dedicated ECU — black, in the module compartment behind the driver's seat — reads engine speed from coil terminal 1 and drives the valve's motor one way or the other. Three things govern it: a microswitch on the linkage only lets it work with the throttle plates closed; a thermistor on the coolant pipe commands a fast idle below 15 °C; and a diode stops another circuit feeding back into the ECU. The throttle body's screws — air screw and two balancing screws — are not used on this car: the air screw must be fully seated. One last instruction, often broken: “do not disconnect the idle speed regulator when adjusting the CO level”. DeLorean workshop manual, fuel and emission section, folios D:01:13, D:05:01 and D:05:02.
A bypass valve built into each throttle plate opens — a solution found nowhere else in the Library. The manual states the problem: “during deceleration, a high manifold vacuum is created behind the closed throttle plates and a lean condition occurs due to the loss of air flow through the air flow sensor. To eliminate this lean condition, which causes high hydrocarbon emissions, a bypass valve is located in each throttle plate”. Those valves “open when the manifold vacuum is above the normal idling vacuum, allowing enough air flow to bypass the throttle plates and permit continued fuel injection”. In other words, on a K-Jetronic the overrun is not handled by cutting the fuel — impossible, the injection is mechanical and continuous — but by letting the air flow sensor breathe. DeLorean workshop manual, fuel and emission section, folio D:09:01.
No, and two devices see to it. A thermal valve in a coolant passage closes below 40 °C and cuts the vacuum to the capsule: “distributor advance is cut out at low temperatures to improve catalytic converter warm-up” — a less advanced engine sends hotter gas out. Above 40 °C the valve opens and passes vacuum to a solenoid valve, itself energised whenever the throttle plates are closed by a linkage microswitch: energised, it shuts the passage. The result: no vacuum advance at idle or on the overrun, which avoids an over-advanced condition. At the distributor, vacuum advance is worth 3° at 5 inches of mercury, 12° at 10 and 20° at 15 — at idle it would change everything. DeLorean workshop manual, fuel and emission section, folio D:08:01; DeLorean workshop manual, electrical section, folio M:01:04.
Almost none, and the manual lists them plainly: “the majority of the fuel injection components are sealed units and cannot be adjusted or repaired”. Not serviceable: the fuel pump (and its inlet check valve, not replaceable), the accumulator, the filter (replace when contaminated), the fuel distributor, the control pressure regulator, the cold start valve, the thermo-time switch, the injectors. Only two exceptions: the primary pressure regulator, whose O-rings are replaceable and whose pressure is adjusted by adding or subtracting spring shims; and the air flow sensor plate, which can be re-centred if it binds and whose rest position is adjustable. The throttle idle stop is preset and “should not be tampered with”. And one prohibition worth repeating: given the pressures involved, “do not attempt to splice fuel hoses”. DeLorean workshop manual, fuel and emission section, folio D:01:16.
With a tool you make yourself, and the manual gives the dimensions: a shank 21.5 mm long, 3.7 mm in diameter, with an 8 by 5 mm head — “an appropriately sized nail cut to the requisite length is aptly suitable”. The method: remove the metering unit and clamp it upside down in a vice, press the sensor plate down to expose the underside of the hole, insert the tool held vertically with pointed-nose pliers, close the plate onto it to hold it, then press on the frame supporting the plate — never on the plate itself, “as serious damage could result” — until the plug is forced out. A new plug goes in after adjustment, the old one is discarded, and the manual warns: “repeated removal will damage the hole to the extent that new plugs will no longer provide a press fit”. On this metering unit the access must be closed again: mixture adjustment is sealed from the factory. DeLorean workshop manual, fuel and emission section, folio D:04:03.
Two things, and the second is surprising. First the emission settings, to be reset before delivery — it is “the responsibility of the dealer” — with a label (part no. 110741) fixed next to the engine setting label. Then: “the full throttle enrichment switch must be disconnected and isolated” at the connector block by the air cleaner. The manual adds a safety warning not to be taken lightly: on automatic cars, do not confuse that switch's light green lead with the kickdown one (light green with a dark green sleeve on early cars, with a dark green tracer on later ones) — “for absolute safety the car should be road tested afterwards to ensure that kickdown operates”. And it works both ways: a car moving back down to low altitude must be reset and the label removed. A temporary visit justifies nothing. DeLorean workshop manual, fuel and emission section, folios D:04:03 and D:04:04.
With a very brief enrichment spike, produced by a delay valve. The control pressure regulator has two vacuum ports connected to the manifold; the lower one goes through a delay valve. Below 40 °C coolant, on acceleration the loss of vacuum reaches the lower chamber later than the upper one: the diaphragm deflects downwards, momentarily opens the regulator, control pressure falls and the mixture richens — “a very short enrichment spike”. After 10 seconds the two chambers equalise and everything returns to normal. Checking the valve: it must take 10 ± 2 seconds to bleed down from 16 to 8 inches of mercury. And the whole circuit only works on a cold engine: the thermal valve feeding it is fully closed above 53 °C and must start to open at 48 °C as the temperature falls. DeLorean workshop manual, fuel and emission section, folios D:01:12 and D:02:01.
Because its control pressure regulator does it on purpose. That regulator contains a bimetal arm and, a little-known detail, two heating elements plus an extra bimetal switch: “when the regulator temperature is below 15 °C, the bimetal switch opens, allowing only one heater to operate, thus increasing the engine warm-up time. Closing of the switch above 15 °C permits both heaters to operate, which reduces that time”. In other words, the colder it is, the longer the warm-up enrichment lasts — exactly as it should. Control pressure therefore runs from about 1.5 bar (22 psi) cold to 3.8 bar (55 psi) warm, and it is the engine's radiant temperature, not the air's, that sets it at start-up: the regulator is mounted on the left valve cover. DeLorean workshop manual, fuel and emission section, folio D:01:11.
Because the thermo-time switch plays two roles at once, and the manual separates them clearly. As a temperature switch: below 35 °C coolant, its bimetal arm closes the contacts and earths the cold start valve, fed from the starter solenoid — above 35 °C the contacts are open and the valve does nothing at all. As a timer: while the starter turns, a built-in heating element warms the bimetal arm and eventually opens the contacts — “if the cranking process takes longer than 8 to 15 seconds, the thermo-time switch opens, deactivating the cold start valve to prevent the engine from flooding”. The exact delay depends on temperature: 7.5 ± 2 seconds at -20 °C, and zero at 35 °C. A detail for hot countries: the car is wired for a hot start relay that is not fitted as standard; installed, it makes the valve inject intermittently when cranking a hot engine. DeLorean workshop manual, fuel and emission section, folios D:01:10, D:01:15 and D:02:01.
By a flap in the air cleaner housing, controlled by temperature. Below 15 °C, the flap is fully open to air heated by the exhaust manifold. As the temperature rises it lets in a mixture of hot and cold air until 25 °C; above 25 °C the flap is fully closed to hot air and fully open to the cold inlet. The flap is neither electric nor vacuum-operated: a wax thermostat inside the housing sets it. This is the kind of component nobody thinks to check and which, stuck on hot air, costs power in summer. (Not to be confused with the 40 °C thermal valve, which belongs to the ignition's vacuum advance circuit.) DeLorean training manual, emission controls chapter, pages 24 and 25.
With a new gasket: tighten to 60 N·m (45 lb·ft), slacken off, pre-tighten to 20 N·m (15 lb·ft), then angle-tighten 115°. For a plain re-torque: slacken off, pre-tighten to 20 N·m, 115°. This is, bar the pre-tightening figure, the Alpine A310 guide's method — 6 m.daN, slacken, 2 m.daN, 115° — and the same final angle as Volvo's 113-117°. Three manuals, three countries, one gesture. DeLorean workshop manual, folio C:02:03.
Main bearing cap nuts: pre-tighten 28 N·m then 75°. Big end cap nuts: 48 N·m. Flywheel bolts 60 N·m with Loctite · converter driving plate 68 N·m with Loctite · sump 16 · crankshaft pulley nut 183 N·m with Loctite · oil pump sprocket bolts 6 · chain tensioner blade bolts 15 · timing cover 15 (bottom bolts with Loctite) · camshaft sprockets 81 · camshaft stop 15 · camshaft sprocket access plug 30 · inlet manifold 15 · spark plugs 20. The comparison is instructive: the big end is given at 48 N·m here, 45-50 at Volvo, 42 or 47.5 at Eagle and 4.5 m.daN on the A310 — the whole family sits in one band. DeLorean workshop manual, folio C:02:03.
The DeLorean workshop manual states the constraint the others imply: the journals are roll-hardened, and “after regrinding, the roll-hardened zone should remain intact over the 140° sector” — two 70° sectors either side, on the zones marked A and B on the crankshaft. This is why the Alpine A310 guide offers only one repair size, at −0.300 mm: beyond that you grind into soft metal and the journal no longer holds. DeLorean workshop manual, folio C:02:06; A310 guide, folio B-10.
The manual gives the worked example, which doubles as instructions: measure at two points, 0.10 mm at A and 0.08 at B; subtract 0.10 from 0.23, leaving 0.13; so pick the seal with the red tag, 0.122 mm average, and fit one of the same thickness under each liner, the castellation (D) bent into its recess (G). Liners go in with the colour tags visible. Two rules then: the protrusion difference between two adjacent liners must not exceed 0.04 mm, and the differences are stepped from cylinder 1 to 3 (or 4 to 6). Finally, number liners, pistons and pins 1 to 6, no. 1 at the flywheel end, so they stay matched to their rod. The seal set is the same as the Alpine A310's: blue 0.087 · white 0.102 · red 0.122 · yellow 0.147 mm. DeLorean workshop manual, folio C:06:03.
At 80 °C, minimum pressure: 2.2 bar (32 psi) at 900 rpm and 4.4 bar (64 psi) at 4,000 rpm. This is the high end of the family — the Alpine A310 guide asks 2 bar at 800 rpm, while Volvo and Eagle settle for about 1 bar at idle, under measuring conditions that are not the same. DeLorean workshop manual, folio C:02:06.
Four figures and one prohibition. Rocker clearance cold: 0.10 mm intake, 0.25 mm exhaust. New head height: 111.07 + 0.15 mm. Maximum bow of the gasket face: 0.05 mm — and “no resurfacing permitted”, as at Alpine, Volvo and Eagle. Valve seats: angle 30° + 0.25 both intake and exhaust, seat width 1.7 to 2.1 mm intake and 2.0 to 2.4 mm exhaust — exactly the early-type Volvo widths. Valve guides: bore 8 to 8.022 mm, nominal outside diameter 13 mm. DeLorean workshop manual, folios C:02:03 and C:02:05.
The two DeLorean manuals appear to contradict each other — and it is a matter of viewpoint, not of engine. The workshop manual writes: “the bank comprising cylinders 1, 2 and 3 is designated the L.H. bank, and that for cylinders 4, 5 and 6 the R.H. bank”, with a plate showing the flywheel at the bottom. The technical manual says the opposite: “the #1 cylinder is located at the right front of the engine”. But it states its convention: “the right and left side of the engine is determined as viewed standing at the rear of the vehicle looking into the engine compartment”. From there, the car's left is on your right: both texts name the same bank. Keep the physical landmark: cylinder no. 1 is the one nearest the flywheel, on the bank on the car's left-hand side; the distributor is driven by the camshaft of the 4-5-6 bank. DeLorean workshop manual, engine section, folios C:02:07 and C:01:01; DeLorean technical manual, general description, page 2.
Because the engine sits behind the rear axle, turned the other way round from a saloon's: “the flywheel (or flexplate) end of the engine is referred to as the front of the engine due to the unique rear engine design. Therefore, the timing cover and drive belt pulleys are located at the rear of the engine”. It is a convention with consequences when reading a procedure: the arrow on the piston crown must point towards the timing cover, that is towards the rear of the car; cylinder no. 1 is the flywheel one, so the closest to the cabin; and the water pump, driven by the crankshaft pulley, also sits at the rear of the engine with the thermostat housed inside it. DeLorean technical manual, general description, page 2; DeLorean workshop manual, engine section, folios C:06:02 and C:13:01.
Cold, at least two hours after the engine has stopped — the condition is written in plain words. The manual gives two cases: after a head has been replaced, run the engine until it reaches normal operating temperature, “i.e. when the cooling fans have switched themselves on”, then wait two hours and re-tighten; after a service exchange engine is fitted, re-tighten while it is still in its transit cradle, far more accessible — “the vehicle need not return to the workshop for cylinder head retightening when the above procedure is observed”. Two steps come first and are easily forgotten: loosen the inlet manifold bolts and those securing the timing cover to the cylinder heads. The re-tightening itself: loosen bolt no. 1, take it back to 20 N·m, then 115° on the graduated disc, and so on in sequence. DeLorean workshop manual, engine section, folios C:05:01 and C:07:09.
Two methods, take your pick, cold and to 0.10 mm inlet, 0.25 mm exhaust. The “on the rock” method: work head by head; when one cylinder's rockers are on the rock — valves rocking, end of exhaust and start of inlet — adjust the rockers the manual's table pairs with that position. The two-position method, quicker: set piston no. 1 at TDC firing (pulley mark against the 0 on the plate, cylinder no. 5's rockers on the rock) and adjust inlets 1, 2 and 4 and exhausts 1, 3 and 6; then turn the crankshaft one full turn and adjust inlets 3, 5 and 6 and exhausts 2, 4 and 5. Everything is set in two positions. Note: the manual's valve timing diagram is quoted with a checking clearance of 0.7 mm, a workshop figure used only to verify the timing — never to run on. DeLorean workshop manual, engine section, folios C:02:04, C:05:02 and C:05:03.
No, and the difference is small but real. With a checking clearance of 0.7 mm, the manual gives for the left bank: inlet opens 9° BTDC, closes 45° ABDC; exhaust opens 45° BBDC, closes 9° ATDC. And for the right bank: 7° / 43° / 43° / 7°. Two degrees between the banks, symmetrical in both cases. It is the signature of a 90° uneven-fire V6 whose crankshaft carries only three crankpins shared by pairs of rods: the firing intervals are not even, and each bank's timing is set accordingly. The technical manual says as much outright: “a 90° V-6 uneven-fire engine”. DeLorean workshop manual, engine section, folio C:02:04; DeLorean technical manual, general description, pages 2 and 3.
Both shafts are identical — but each goes on its head by turning the complete assembly round, never otherwise: “the position of the rocker shaft must not be reversed because the oil feed holes (A) will be blocked; the rocker shafts must be fitted with their oil holes facing downwards”. It is the shaft itself that feeds the whole valve train through calibrated holes — fit it the wrong way and you condemn the lobes and the rocker pads. The assembly order is just as strict: snap ring, bearing with the flat on the boss facing the snap ring, spacer spring, rocker with its adjusting screw on the left, 5.35 mm spacer, rocker with its screw on the right, 8.2 mm spacer, then bearing. The galley plugs at the ends are pressed in and cannot be removed. DeLorean workshop manual, engine section, folios C:05:06 and C:05:07.
Hot, as on the Eagle: the pin is an interference fit in the small end and free in the piston. Heat the small ends on an electric hot plate — “the required temperature of 250 °C is restricted to the small end zone only” — using a piece of solder melting at about 250 °C as a thermometer: when it runs, it is ready. Then everything is quick: wipe off the droplet, insert the guide, offer the rod with one hand, press the pin home with the other until the guide bottoms. Orientation depends on the bank: on the left (1-2-3) bank the rod's extended flange (E) faces downwards on the plate; on the right (4-5-6) bank it faces upwards. That flange exists because the big ends are offset: two rods share one crankpin. And the piston's arrow always looks towards the timing cover. DeLorean workshop manual, engine section, folios C:06:04 and C:06:05.
Three rules, and a fourth that comes first: the rings arrive with their gaps pre-set and must be free in their grooves. Then: (1) faces with markings face upwards, towards the combustion chamber; (2) the expander gap of the scraper ring goes in line with the centre of the gudgeon pin, and the scraper's own ring gaps are offset 20 to 50 mm from each other; (3) the top ring and the taper compression ring are spaced 120° from the expander gap. Thicknesses: 1.5 mm top ring, 2 mm taper compression, 4 mm scraper. And the piston goes into the liner with a ring clamp, liner and piston assembled away from the block. DeLorean workshop manual, engine section, folios C:02:06 and C:06:06.
“Grooved shells are fitted to the block. Shells without oil grooves are fitted to the main bearing caps” — the groove carries the oil, so it belongs on the side the oil comes from. The shells, mains and big ends alike, are aluminium-tin. The thrust half washers go in with their oil grooves facing the crankshaft flange, nominal size 2.30 mm, and four thicknesses exist (2.30 · 2.40 · 2.45 · 2.50) to bring end play between 0.07 and 0.27 mm, measured with a dial gauge. Front and rear caps go on with boss (A) towards the timing cover, held by blocks J 28853 while the play is checked. Tightening: to torque from the centre main outwards, then 75° of angle. DeLorean workshop manual, engine section, folios C:02:05, C:07:05, C:07:06 and C:07:08.
Because with the block it forms the gearbox mating face: “it is essential that the bottom casing and cylinder block are absolutely flush at the clutch end in order to avoid distortion of the clutch housing when the gearbox is fitted”. The method is neat and needs no special tool: offer up the casing with every fastener loose, then align it either by offering up a clutch housing and moderately tightening its four bolts, or with two straight edges laid on the block — in the latter case check the alignment after tightening. It is the same concern as on the Eagle Premier's 3.0L, which demands a dedicated alignment plate for it: on these bedplate V6s, the bottom casing is a structural part, not a cover. DeLorean workshop manual, engine section, folio C:07:07.
By first making the engine safe: crankshaft keyway vertical and piston no. 1 15 mm down its bore, on compression — “to avoid the risk of contact with the valves”. Then, left bank first: turn the crankshaft to bring the centre of the keyway onto the centre line of the left bank, fit the chain to the camshaft sprocket with the chain's dual mark astride the sprocket's timing mark, then over the rear set of teeth of the crankshaft's double sprocket, single chain mark in line with the sprocket's timing mark. Right bank: turn the crankshaft 150° — the sprocket mark comes in line with the oil pump cover's bottom bolt — and repeat on the front set of teeth. The tensioners are set by turning their ratchet clockwise with a screwdriver, and the manual adds an instruction that gets forgotten: “do not assist the tensioners to find their operational setting”. DeLorean workshop manual, engine section, folios C:07:09 and C:07:10.
The manual lists them, short and final: “Components which must be changed at each dismantling: flywheel fixing bolts · convertor driving plate fixing bolts · big-end cap nuts”. The flywheel and drive plate bolts are self-locking — “they must be renewed after each dismantling; smear the threads with Loctite”. To these the procedures add everything that seals: liner base seals (never reused), the O-rings of the oil pick-up pipe and water pump, the cork sump gasket, the mixture regulator's gaskets when the distributor comes off, and the head gaskets, which go on dry. A useful detail: the service crankshaft comes without the clutch shaft spigot bearing — it must be fitted, bonded with Loctite, if the engine is mated to a manual gearbox. DeLorean workshop manual, engine section, folios C:02:07, C:07:05 and C:07:10.
Yes, but under a condition few grinders know: the main journals are roll-hardened, and “after regrinding, the roll-hardened zone should remain intact over the 140° sector”. In other words the journal cannot be taken down all the way round: the grind must spare the treated arc, or the journal loses its surface hardness. The sizes: nominal diameter 70.062 mm, regrind diameter 69.762 mm — 0.300 mm less, a single repair size — with a tolerance of 0 to 0.019 mm. The shells themselves are aluminium-tin. Compare the Eagle manual, which for the same engine offers one bearing size only and refers to factory codes P, M or PM for crankshafts that left the works already undersize. DeLorean workshop manual, engine section, folios C:02:05 and C:02:06.
With chemical paint stripper, not a scraper: on an aluminium alloy block and heads, a blade scores the gasket face. The instruction comes with an even more important warning: “take care not to introduce any foreign matter into the oilways (4) and (5) which might block the rocker arm oil jet holes and lead to excessive wear of cam lobes and rocker fingers”. On this engine the valve gear's oil arrives through the rocker shaft and leaves through small calibrated jets: one scrap of gasket and a lobe is destroyed. The Eagle manual says the same thing differently — a wooden or plastic scraper only, never metal. DeLorean workshop manual, engine section, folios C:05:04 and C:06:02.
Three things. One: the pump body is not a spare part — it is a machined portion of the upper crankcase, and “the complete oil pump assembly must be changed if any particular part is worn”. Two: to free the cover, “never unstick the cover by tapping the release valve boss” — you would distort it. Three: on reassembly tighten the cover bolts progressively, checking that the gears still turn freely, and prime the pump by injecting oil with an oil can through hole (A) below the filter connector, filter removed. The pump sprocket bolts and the timing cover's bottom bolts get Loctite. Checking afterwards, engine hot at 80 °C: 2.2 bar (32 psi) minimum at 900 rpm and 4.4 bar (65 psi) at 4000, measured with tools J28872/J28873 in place of the pressure sender — which goes back with a new copper washer. DeLorean workshop manual, engine section, folios C:10:01, C:10:02 and C:11:01.
By removing the mixture regulator — the K-Jetronic fuel distributor, which blocks the way: “the mixture regulator must be removed to reach the distributor”, and its gaskets must be renewed on reassembly. Before pulling the distributor, mark two things, which saves having to re-time the ignition: the position of the distributor body relative to the cylinder head and that of the rotor arm relative to the head. If in doubt, the fallback: piston no. 1 at TDC firing — crankshaft pulley and calibrated bracket marks aligned — then the rotor against the “no. 1 cylinder” mark on the body; since the distributor is driven by a spiral gear, allow for the rotor turning as it goes down. A useful reminder: the pulley has two slots, one for cylinder no. 1 TDC and one for no. 6 — so either can be strobed. DeLorean workshop manual, electrical section, folios M:01:01 and M:01:02.
0.8 to 1.1 MPa, that is 8 to 11 bar (114 to 156 psi). And the manual boxes the conditions, without which the reading means nothing: warm engine, throttle fully open, and a starter turning speed of 250-300 rpm. Precaution before starting: disconnect the cable from terminal 15 on the ignition coil. Plugs go back in at 12 ± 2 N·m. Volvo service manual, section 2, page 29.
In two crankshaft positions, as on the A310 — but with a mark to know about: the pulley carries TWO marks, “1” = TDC cylinder 1 and “2” = TDC cylinder 6. Position 1: bring mark “1” to the zero of the scale, both rockers on cylinder 1 must have clearance — then adjust intake on cylinders 1, 2 and 4 and exhaust on cylinders 1, 3 and 6. Position 2: one turn of the crankshaft in the normal direction, mark “1” back on zero but cylinder 1's rockers with no clearance (overlap) — adjust the rest. 36 mm socket on the pulley. Volvo service manual, section 2, pages 32 and 51.
Because it ends up in the lubrication circuit. The manual allows — indeed recommends — a thin coat of silicone (P/N 116 1048-2) at the valve cover / cylinder block / timing gear case junction to seal that three-way joint, then immediately warns: “do not use too much silicone otherwise it may enter into the lubrication system and block the oil channels”. The gaskets themselves are secured with sealer P/N 116 1026-8, and the covers torqued to 10-15 N·m. Volvo service manual, section 2, page 33.
Having to strip and clean the whole engine. Two warnings follow each other in the manual. First: “the cylinder head must not be lifted directly up” — lever it off with a hammer shaft, and rest it on blocks so the gasket faces are not damaged. Then, and this is the real danger: “make sure that the liners do not separate from their seals in the lower liner seat. If this happens, coolant can flow down into the crankcase, and it will be necessary to remove, disassemble and clean the engine thoroughly”. Hence the 5093 liner holders, to be fitted as soon as the head gasket is off. Volvo service manual, section 2, page 40.
By removing the left-hand valve cover and looking at the tensioner: “if the tensioner pin protrudes by 4 or more notches (8 mm) the chains should be renewed”. The manual adds the consequence, and it goes beyond timing rattle: “excessively worn chains can cause low oil pressures, and engine damage may result” — because oil leaks past the pistons of tensioners that have reached their end stop. It is in fact the first check the “low oil pressure” chapter sends you to. At the slightest doubt, remove the timing gear case and inspect. Volvo service manual, section 2, pages 57 and 89.
Far more than the chains. The manual requires the sprockets and the strainers behind the tensioners to be changed too, and a move to the late type for tensioners, straight dampers and bent dampers. The rule that goes with it is strict: “late type chain tensioners may only be used with late type chain dampers”. The two are told apart by eye: the early damper is without an oilway (0.4 mm orifice, 174 mm long), the late one with (1.2 mm, 220 mm). Special case: on early B27s, up to mid-1976, the bent damper had a small mounting. ⚠️ Never dismantle a tensioner — if the lock falls out, the tensioner must be replaced. Volvo service manual, section 2, pages 58 and 62.
On the take-off on the left-hand side of the engine, in front of the oil filter — and nowhere else. The manual is categorical: “if the pressure is measured anywhere else, the results will be invalid”. Adapter P/N 464592-5 lets you fit a gauge there. Warm engine and new filter, expect at least 0.1 MPa at 900 rpm and 0.4 MPa at 3,000 rpm. Volvo service manual, section 2, page 87.
A leak on the intake side of the oil pump. The manual names three suspects: the O-rings between cylinder block and sump, those between sump and oil strainer, and — on early engine versions — the guide sleeve between block and sump, which may have fallen out; oil then leaks past the upper O-ring. Later cars have a collar in the sump that stops the sleeve falling. If the oil is clean but pressure stays low at ALL the rockers, the cause is elsewhere: internal leakage or a tired pump — then check chains, strainer and pump. Volvo service manual, section 2, pages 88 and 89.
The manual gives three causes, all oil-related: incorrect oil quality or viscosity — “it is important that the correct oil is used and that it is changed sufficiently often with regard to driving conditions” —, contaminated oil (camshaft grindings, coolant, petrol), and insufficient oil supply to the rockers. Hence the warning that follows: “it is absolutely essential that the engine is cleaned thoroughly before replacing damaged or worn camshafts/rocker arms” — otherwise the old one's debris destroys the new. The flushing procedure is simple: drain, new filter, ten minutes warm-up, drain again and another filter. There are also two types of camshaft, the part number stamped on the end. Volvo service manual, section 2, pages 68 and 69.
Hot against cold, and fast. Guides come in four sizes, identified by grooves: standard no groove, oversize 1 one groove, oversize 2 two grooves, oversize 3 three grooves — always take the size above the old one, and ream the seat with the matching reamer. Then: head heated to about 150 °C, guide cooled to about −70 °C with liquid carbon dioxide (protective gloves), then pressed in with the drift — “this must be done very quickly, within 3-4 seconds”, the head on a sloping surface so the guides are vertical. Preliminary check: guide-to-valve clearance must not exceed 0.15 mm, measured with a dial indicator on new valves raised 5 to 10 mm. Volvo service manual, section 2, pages 43 and 44.
Intake 29.5°, exhaust 44.5° — and the manual adds to grind the end of the valve stem flush as well. Two rules frame the job. First the order: “valve guides must always be renewed before replacing seats”. Then the seat's interference in the head, which must be between 0.070 and 0.134 mm: measure the recess with an internal micrometer and choose from three oversizes. The seat is also cooled to −70 °C and tapped in within 3 to 4 seconds. After replacement, seats to be milled and valves ground in. Volvo service manual, section 2, pages 45 to 47.
By their colour code: two types are used depending on engine, marked GREY and GREEN. They are checked under load, length by length: 47.2 mm free, 40.0 mm under 233 to 268 N, 32.2 mm under 521 to 585 N. A spring out of tolerance is replaced — and the two codes are not mixed on one engine. To check in the same pass: camshaft end float, which must not exceed 0.5 mm (beyond that it is the locking fork that is replaced), and rocker-to-shaft clearance, 0.012 to 0.054 mm for new parts. Volvo service manual, section 2, pages 43 and 47.
Three, easily missed. There are two types of bolt (P/N 245083-1 and 246949-2) and the rocker bridges are different left and right — do not swap them. The bolts “must be clean and oiled”, in line with the manual's general rule on torque. Finally the rocker circlips face forwards on the left-hand side and rearwards on the right. A fitting detail: the guide sleeves are held with a 3 mm drill so they are not forced down as the head goes on — a drill removed before the bolts go in. Volvo service manual, section 2, pages 48 and 49.
By the marks, and they are not read the same way at both ends. Crankshaft and left camshaft first: the crankshaft key points towards the left camshaft, the camshaft groove points upwards, and cylinder 1's rockers must have no clearance. Then, for each chain: the camshaft sprocket mark goes BETWEEN the two chain marks, and the chain mark OPPOSITE the crankshaft sprocket mark; the chain is then stretched on the pulling side, the one bearing against the straight damper. The tensioner and damper bolts get locking fluid (P/N 116 1053-2), and the timing gear case's four bottom bolts locking fluid 116 1056-5, torqued to 10-15 N·m. Volvo service manual, section 2, pages 63 to 65.
So the key does not fall into the sump. The manual asks for it explicitly before removing the crankshaft pulley — and reminds you in passing that the pulley carries two timing marks, “1” for cylinder 1's TDC and “2” for cylinder 6's. Removal is with a 36 mm socket, the flywheel locked by sector 5112 on the bellhousing. On reassembly two types of nut exist and the torque depends on it: 160-180 N·m for the 40 mm nut (1975-1977), 240-280 N·m for the 45 mm one (from 1978). Volvo service manual, section 2, pages 73 and 74.
The manual makes it a short, imperative list: new gaskets and seals, new flywheel bolts — the flywheel only fits one way round, its holes being asymmetric, and is torqued to 45-50 N·m — and, on manual gearboxes, a new crankshaft pilot bearing. On injected engines it also asks you to check the injector rubber seals: gone oval, they cause air leaks, erratic idle and hard starting. The pressure plate is tightened crosswise, a few turns at a time, so it is not distorted. Volvo service manual, section 2, pages 76, 83 and 84.
They are factory-set and should be left alone — unless the lower part of the air flow sensor has been replaced, or the engine runs poorly. In that case: screw screws 2 and 3 fully in, then unscrew no. 2 by one and a half turns for the left bank (cylinders 1, 2, 3) and no. 3 by 5.0 turns for the right bank (4, 5, 6). ⚠️ Special case of the B28F with constant idle speed system: the idle screw (1) is screwed fully in, and screws 2 and 3 must be “tightened until the heads shear” — the manual notes in a box that “failure to shear adjustment screw heads may contravene USA Federal laws”. Volvo service manual, section 2, page 98.
The specification page states that the auxiliary air valve is “fully open at -30 °C = -22 °F, fully closed at +17 °C = +158 °F” — we read it off the plate. But 158 °F is 70 °C, not 17. And the inspection chapter, forty pages further on, settles it: “fully closed at +70 °C (158 °F)”. So it is a transposed figure — 17 for 70 — in the table, and the right value is 70 °C. The error is not harmless: at 17 °C you would condemn a perfectly good valve on any engine checked in mild weather. The real test of health lies elsewhere, and it is simple: “the valve is electrically controlled and should be fully closed after 5 minutes of engagement at an ambient temperature of 20 °C”. A reading rule, the same as for the American manuals: when two units contradict each other, cross-check against the procedure. Volvo workshop manual, section 2 (23), CI fuel system, pages 10 and 30.
Because they have an impulse relay in the start injector circuit. On 1981-1983 models, “the start injector is also controlled by an impulse relay so that the engine receives additional fuel during warm starts”. Its rhythm is specified: it engages the injector after about 1.5 seconds, then 0.1 s injection, 0.3 s pause, 0.1 s, 0.3 s… — enough to prime without flooding. And the manual notes it may have been retrofitted to 1979-1980 B27Es, 1978-1979 B27Fs and 1980 B28Fs: on a used car, look for it before diagnosing. A testing consequence: to check the start injector and thermal time switch alone you must unplug the impulse relay's connector, otherwise you read the relay's rhythm instead of the switch's timing. Volvo workshop manual, section 2 (23), CI fuel system, pages 10, 25 and 26.
Because of its thermal time switch, whose cut-out point is different: 35 °C on B27E, B28E and B28F, but 15 °C on the B27F. The direct consequence is written at the head of the inspection chapter: “B27F: the temperature must be below 15 °C to be able to check the thermal time switch in the car” — in a heated workshop the test is simply impossible without chilling the engine. The manual adds two useful points: the replacement part is a 35 °C one, so a repaired B27F may behave differently from new; and the cut-out point and the engagement time at -20 °C are stamped on the side of the switch, with tolerances of ± 4 °C and ± 2 seconds. For the record, the reference engagement time is 7.5 seconds at -20 °C, falling to zero at the cut-out point. Volvo workshop manual, section 2 (23), CI fuel system, pages 10, 24 and 25.
Flush it with white spirit, and the manual devotes a whole procedure to it. The symptoms first: “engine stoppage, difficult cold starting, erratic idling, low output”. The kit: about 6 litres of white spirit, two drain pans, two one-metre hoses, clamping pliers. The method: drain the tank, pour in 4 litres of white spirit, rock the car so it mixes with any water, drain, refill with clean petrol and fit a new tank pump filter; then feed the main pump from a jar of white spirit, injectors removed and returns into a vessel, and push 1.5 litres through with the sensor plate held open. The detail that makes the difference: you need TWO new fuel filters — one before flushing, one after — “because some of the water which has condensed in the system is absorbed by the filter when the system is flushed”. Volvo workshop manual, section 2 (23), CI fuel system, pages 19 to 23.
Three, and they govern the validity of every reading. One: the engine must be cold, “below +30 °C”, since control pressure, auxiliary air valve and start injector all have to be checked cold. Two: unplug the control pressure regulator and auxiliary air valve connectors — “otherwise these components heat up during the inspection and the results will be invalid. It can take as long as an hour for a component to cool down again”. Three: check the mechanical and electrical side first, because the manual refuses to let you into the injection before compression, valve clearances, vacuum hoses, air filter, intake and exhaust tightness, plugs, leads, distributor cap, coil and timing have been checked — plus, on the cars concerned, the constant idle speed system. Two standing instructions go with it: absolute cleanliness and new gaskets every time. Volvo workshop manual, section 2 (23), CI fuel system, pages 18 and 24.
By ear, listening to the injectors — and the diagnosis comes in three cases. With the ignition on, briefly depress the plate: “injectors should only buzz when the plate is depressed; on release, the plate returns to rest and the buzzing stops”. If the injectors buzz with the plate at rest, the control plunger in the fuel distributor has jammed: clean or replace. If they do not buzz with the plate depressed, line pressure is at fault. And if the plate itself binds, the sensor is reconditioned. Two traps are flagged: “control pressure offers some resistance when depressing the plate, do not mistake this for jamming” — exactly the DeLorean manual's warning — and, on 1975-1978 B27Es, the plate must be LIFTED, not depressed, the sensor's architecture being inverted. Volvo workshop manual, section 2 (23), CI fuel system, page 27.
One a minute, no more: “make sure that the start injector does not leak. Max rate = 1 drop per minute. If greater, replace the injector”. It is the check everybody forgets, and it explains impossible hot starts and drowned plugs: a dripping start injector enriches permanently, hot engine or cold. The test is done with the injector removed (5 mm Allen key), held over a container, ignition on, pump running. In the same series of checks: the ordinary injectors have an opening pressure of 300-360 kPa (type 005, 1975-1978) or 320-380 kPa (type 013, 1979-1983), with no leakage permitted below 240 and 260 kPa respectively — the number is stamped on the injector's side. Volvo workshop manual, section 2 (23), CI fuel system, pages 11 and 26.
A steel ball, tapped in with tool 5232: “if CO has been adjusted, seal the air-flow sensor: place the steel ball in tool 5232 and tap it into position”. The rule applies to 1981-1982 USA and 1982 Canada B28Fs, whose mixture screw is factory-sealed — the underbonnet emissions plate on those cars stops quoting the CO figure altogether. It is Volvo's answer to the DeLorean's tamper-proof plug, only more final: a driven ball is not withdrawn, it is drilled out. The chapter's special tools are worth knowing: besides the sealing tool, a 5102 wrench for the CO screw, a 5151 adapter for the F engines' CO meter (with a lever selecting the cylinder bank), a 5170 test relay to run the pump without the engine, and a 9934 injector tester. Volvo workshop manual, section 2 (23), CI fuel system, pages 12 and 104.
Hot air only up to 15 °C, an intermediate position after that, cold air only from 25 °C. Those are, to the degree, the thresholds of the DeLorean's wax-thermostat flap — same engine, same intake logic. The check needs nothing dismantled: “the position of the shutter at different temperatures can be checked by observing the ends of the spindle”; for a more exact check, remove the housing and test the thermostat in warm water. And the repair is blunt: “if defective, replace the complete shutter housing and thermostat” — nothing is changed separately. A flap stuck on hot air costs power in summer and has the engine breathing at 40 °C instead of 20; stuck on cold air, it makes the engine hesitate when cold. Volvo workshop manual, section 2 (23), CI fuel system, page 106; DeLorean workshop manual, folio D:07:01.
By pressing in a new nipple — never the old one: “always use new nipples when reconnecting fuel lines since the sealing surfaces are easily damaged on removal”. The method is homespun and effective: cut the line square, about 20 mm from the old adapter, slit the outer shielding hose over 40 to 50 mm, clean and blow the inside out, then heat the line with hot air — a hair dryer will do — and press the new nipple in with pliers 5012 (or 5013 for larger sizes), lubricated with white spirit if needed. Fold the shielding back and fit a strip clamp. A useful piece of history: “in March 1982, one-piece polyamide fuel lines were introduced instead of steel ones” — for cost reasons, but also because they cut the fuel pump's noise; they are the only ones still stocked, including for cars from 1978 on. Volvo workshop manual, section 2 (23), CI fuel system, pages 107 and 108.
The Constant Idle Speed system, fitted only to 1981 USA California and Japan B28Fs, then to all 1982 B28Fs. A control unit housed in the Y-shaped water distribution tube under the manifold drives an air control valve replacing both the auxiliary air valve and the idle screw. Speed: about 1100 rpm at -20 °C, falling as the engine warms and settling at 900 rpm — tolerance 850-950 in 1981, tightened to 880-920 in 1982. The workshop consequence is final: “the idle adjustment screw and balance screws must always be screwed in fully on engines with the constant idle speed system. The balance screws are of shearhead type and must be tightened until the heads break off”. In other words, on these cars there is nothing left to adjust at idle — and the manual lists the external faults that mimic a CIS failure: ignition timing, CO content, air leaks, a misadjusted microswitch, the temperature sensor, blocked crankcase ventilation. Volvo workshop manual, section 2 (23), CI fuel system, pages 11, 86, 87 and 104.
Against vapour lock. “A tank pump was introduced in 1977 to improve fuel delivery — it was also installed on some earlier vehicles. It supplies fuel to the main pump under constant pressure and incorporates a non-return check valve which minimises the risk of vapour lock”. A suction pump drawing hot fuel ends up pumping vapour; a pump that pushes solves it. It draws only 1 to 2 amps, against 9.5 A maximum for the main pump, whose output rises from 100 l/h (1975-1979) to 120 l/h (1980-1983) at 500 kPa. Two further changes to the same circuit are worth knowing: a new pressure regulator arrived in 1978 which “blocks the fuel return line when the engine is switched off” — better rest pressure retention — and, the same year, the two pump relays gave way to a single electronic relay. Volvo workshop manual, section 2 (23), CI fuel system, pages 11, 15 and 82.
By watching its link rod at different speeds and temperatures, and the rule fits in one sentence: “the EGR valve should only open at part throttle with a warm engine”. So: closed at all engine speeds when cold, that is coolant below 55 °C — if it opens then, the thermostat is defective — and open at part throttle once warm. The symptom of a valve opening at the wrong moment is clear: erratic idle, possibly stalling. The direct check is with a vacuum pump on the valve: it must open. Volvo fitted four different EGR systems by engine, year and market — on/off, and three stepless ones —, each with its own engine list. Volvo service manual, section 2, pages 108 to 116.
With no chemicals and no complicated stripping: “tap all parts lightly with a soft mallet to remove carbon deposits, remove dirt from channels and nipples with a screwdriver and blow parts clean with compressed air”. The manual stresses one point: “special care should be taken to ensure that the valve seat in the EGR valve is free from carbon”. On F engines, the dashboard indicator lamp must be reset after cleaning. And a diagnostic rule not to forget: the Pulsair system must be disconnected and plugged before any CO check, or the results are false. Volvo service manual, section 2, pages 107 and 117.
Two things, and the manual puts them in capitals. “The air pump must not be lubricated or dismantled” — if defective it is replaced, full stop. And: “never plug or obstruct the diverter valve outlet since this can cause severe damage to the air pump”. Checking the diverter valve is simple: at idle air must blow from port A; raise the speed to about 3,500 rpm and snap the throttle shut — the flow from A should stop for a few seconds and air blow from the side vents B. If not, check the vacuum hose between valve and intake manifold before condemning the valve. Volvo service manual, section 2, pages 105 and 106.
With “Never-Seez” anti-seize paste (P/N 116 1035-9) on the threads — and one precaution: “make sure that no paste enters the slot as this will inhibit function of the Lambda-sond”. Torque: 55 N·m. Then the warning lamp must be reset: it is operated by a switch on the back of the speedometer and connected to the odometer — it is what reminds the owner it is time to replace the sensor. Symptoms of a failing Lambda system, as listed by the manual: hard starting especially when hot, rough running, rough idle when cold below 15 °C (thermal switch), high fuel consumption, and on some B28Fs poor acceleration when cold below 55 °C (pressure differential switch). Volvo service manual, section 2, pages 127 and 139.
Not with the radiator. Its list of possible causes begins with the system itself — coolant leakage, expansion tank cap opening pressure too low, radiator blocked by insects, air bypassing the radiator, air guide beneath the radiator missing (it was not standard in 1975) — then moves to the settings: ignition too retarded, which raises combustion temperature, CO content too low, which does the same, and idle speed too low. The pressure test goes between radiator and expansion tank: cap opening at 65-85 kPa, and the pressure must not drop noticeably in 30 seconds. Belts: they must deflect 5 to 10 mm midway between pulleys, and the water pump is torqued to 15-20 N·m. Volvo service manual, section 2, pages 143, 145, 149 and 150.
Careful, there are two different clearances and it is the model year that decides, not the engine type. Type 1: intake 0.10-0.15 mm cold (0.15-0.20 warm), exhaust 0.25-0.30 cold (0.30-0.35 warm). Type 2: intake 0.20-0.25 cold (0.25-0.30 warm), exhaust 0.30-0.35 cold (0.35-0.40 warm). The manual's table: B27A 1976-1979 type 1 · B28A 1980 type 2 then 1981-1982 type 1 · B27E 1975-1978 type 1, 1979-1980 Sweden and Australia type 1 but other markets type 2 · B28E 1981-1983 type 1 · B27F 1976-1979 type 1 · B28F 1980 type 2, then 1981-1982 type 1. The same B28F therefore changes clearance from one year to the next. Volvo service manual, section 2, page 6.
In ten stages, the last of which is done with the engine warmed then cooled: 1) 10 N·m · 2) 30 N·m · 3) 60 N·m · 4) wait 10 to 15 minutes · 5) slacken the bolts · 6) 15 to 20 N·m · 7) angle-tighten 113 to 117° · 8) warm the engine to operating temperature · 9) cool the block 30 minutes · 10) slacken then retighten the bolts one at a time in sequence, repeating stages 6 and 7. The torques assume oiled bolts: a degreased part must be oiled before assembly. Compare with the other two manuals in the Library: the Alpine A310 does 6 m.daN, slacken, 2 m.daN and 115°; the Eagle Premier does 60 N·m then, bolt by bolt, full slacken, 40 N·m and 180° ± 20°. Three methods, three engines — and a final angle that is remarkably alike. Volvo service manual, section 2, page 9; reconditioning booklet, page 12.
Through the lower crankcase, nut by nut, in five stages: 1) all nuts to 30 N·m · 2) slacken nut no. 1 · 3) retighten it to 30-35 N·m · 4) angle-tighten 73 to 77° · 5) slacken and retighten each of the other nuts the same way, in order. This figure matters beyond Volvo: the Alpine A310 guide contradicts itself on this point — 3 m.daN then 75° at folio B-10, 2 m.daN then 115° at folio B-12a — and it is the first version that the Volvo manual corroborates, to within a degree. Volvo reconditioning booklet, page 12.
In the “repairs and maintenance” manual, the torque table lines up four labels against three values — and the “1978–” crankshaft front end row is left blank. Read literally, it gives “Big end bearings 160-180 N·m”, which would destroy a rod. The reconditioning booklet, in the same Library, prints the same table correctly: connecting rod bearings 45-50 N·m, crankshaft front end 160-180 N·m for 1975-1977 and 240-280 N·m from 1978 (the nut goes from 40 to 45 mm across flats). It is a one-line shift, and it is the second document that proves it. Volvo service manual, section 2, page 9; reconditioning booklet, page 12.
No, and it is striking: four manuals, four manufacturers, thirteen years apart, and the same prohibition. Alpine, 1977: permissible distortion 0.05 mm, “no skimming allowed”. Volvo, 1983: max warp 0.05 mm over 100 mm, “do not level a warped cylinder head, replace it”. DeLorean, 1982: maximum bow of the gasket face 0.05 mm, “no resurfacing permitted”. Eagle, 1990: max warp 0.051 mm, “NOT RESURFACEABLE”. The new head heights fall into two pairs — 111.07 mm at Volvo and at DeLorean (the 2,849 cc), 110.87 at Alpine and 110.83 at Eagle: it is the same architecture, and it is not to be machined. A310 guide folio B-6a; Volvo manual section 2 page 5; DeLorean workshop manual folio C:02:03; Eagle manual folio 9-68.
Warm engine and new oil filter: 0.1 MPa (1 bar) minimum at 900 rpm and 0.4 MPa (4 bar) at 3,000 rpm. Capacity: 6.0 litres excluding the filter, 6.5 litres including, about one litre between the dipstick's min and max marks. The cross-check shows two families, not one exception: Volvo asks 1 bar at 900 rpm and the Eagle Premier 1 bar at 790, while the Alpine A310 guide demands 2 at 800 rpm and the DeLorean workshop manual 2.2 bar at 900. The measuring conditions differ too — 'warm engine and new filter' at Volvo, 'thermostat open, 89 °C' at Eagle, 'at 80 °C' at Alpine and DeLorean. So you read the figure from YOUR manual, never the neighbour's. Volvo service manual, section 2, page 10.
Quality API SF/CC in the USA and Canada, with a prohibition set in bold in the manual: “Under no circumstances may SE/CD oils be used”. On other markets, API SE/CC or SF/CC. On viscosity, the manual gives an ambient-temperature chart and adds a useful recommendation: SAE 15W/50 or 20W/50 for severe use — high oil consumption, high oil temperatures, mountain driving with frequent decelerations, fast motorway work — watching the lower temperature limit. The carburettor damper cylinder takes SAE 10W-40 (or 10W-50). Volvo service manual, section 2, page 10.
The manual prescribes genuine Volvo coolant, “type C”, diluted 50/50 with clean water, and gives the reason: “since we use aluminium in our engines, active corrosion protection is necessary”. Two rules follow: never fill the system with water alone, and change the coolant regularly because the corrosion inhibitors lose their effect. Capacity about 11 litres. The expansion tank cap opens at 65-85 kPa overpressure and 7 kPa underpressure. Three thermostats exist: marked 82 (opens 81-83 °C, fully open 90-94), 87 (86-88, 95-99) and 92 (91-93, 100-104). ⚠️ This “type C” is Volvo's own product for its aluminium engines: it has nothing to do with the red “Type C” fluid of the Renault 25 phase 2, which the association advises against. Volvo service manual, section 2, page 12.
Because “nearly all of the B27/28 engine is made of aluminium alloy, and the threads are tapped directly into the alloy” — hence, the manual says, the extreme importance of tightening all bolts to the specified torque. It even codes its typography, which you need to know to read it: a torque printed in bold means a torque wrench must be used; the same torque in normal type gives the correct value but without requiring the tool. Volvo service manual, section 2, page 4; reconditioning booklet, page 4.
Because the pin is an interference fit in the piston, and the piston is deformed when it is driven out. The manual says it plainly: “once a piston has been removed it may not be used again”. This is an architectural difference from the other PRVs in the Library: on the Alpine A310 the pin is “tight in the connecting rod and turning in the piston”; on the Eagle Premier it is heat-shrunk into the rod, whose small end is expanded on a 1,500 W hot plate. At Volvo it is the other way round — the pin turns in the rod with 0.020 to 0.041 mm clearance. Three consequences: piston and rod are only separated to replace pistons or liners; liner, piston and pin are supplied in matched sets of six; and connecting rods are sold in sixes, all to be replaced at the same time. Volvo reconditioning booklet, pages 7 and 32.
Mahle pistons only on the B28 (the B27 accepts Demolin or Mahle). Weight 455 ± 3 g, with a maximum difference of 6 grams between pistons in the same engine. Overall height 62.8 mm on A and F engines, 65.3 mm on the E; from gudgeon pin centre to crown, 38.8 and 41.3 mm. Diameter measured 8 mm from the bottom edge and at right angles to the pin bore, by class: A 90.970-90.980 · B 90.980-90.990 · C 90.990-91.000 mm. The pin bore is colour-matched too — blue 23.510-23.513, white 23.507-23.510, red 23.504-23.507 — with a pin of the same colour. Ring gap, measured 15 mm from the bottom of the cylinder: 0.40-0.60 mm for both compression rings, 0.38-1.45 for the oil ring. Volvo reconditioning booklet, page 7.
Because B27s were built with pistons from two suppliers — Demolin and Mahle — whose fitting clearances have nothing in common: 0.090 to 0.110 mm for a Demolin, 0.020 to 0.040 mm for a Mahle. A factor of three. Apply the Mahle figure to a Demolin-built engine and you condemn a healthy one; apply the Demolin figure to a Mahle and you let real wear through. The measuring point changes too: 8 mm from the bottom edge for all Mahle pistons, 11 mm for a 1976-1978 B27F on Demolin pistons, 8.5 mm from the bottom of the oil ring groove for other Demolins — always at right angles to the pin bore. The B28s only ever had Mahle. First job before any measurement: identify the piston's make. Volvo B27 / B28 engine reconditioning booklet, pages 4, 5, 26 and 27.
Three types, identified by the part number marked on the front end, and their lifts differ: type 1, 5.144 mm on the left and 5.059 mm on the right — the two banks are not identical; type 2, 6.004 mm both sides; type 3, 5.96 mm both sides. The timing check is made on a cold engine with the clearance set to 0.7 mm on the intake valves of cylinders 1 and 6: they must then open at 9° ± 3 BTDC (cylinder 1) and 7° ± 3 (cylinder 6) for type 1; 9° ± 3 both sides for type 2; 8° ± 3 for type 3. That 0.7 mm checking clearance is exactly the one the DeLorean manual uses for the same verification: same engine, same method. Volvo B27 / B28 engine reconditioning booklet, page 8.
With base shims identified by paint marks, and the method is numerical. Fit the liner without a shim first and measure its height at three points: the spread between the three readings must not exceed 0.05 mm, otherwise there is dirt under the flange. Take the highest figure, subtract it from 0.23 mm — the target, “as near as possible to 0.23” within the 0.16-0.23 range — and choose the shim equal to or just under the result. The four shims: blue 0.070-0.105 · white 0.085-0.120 · red 0.105-0.140 · yellow 0.130-0.165 mm. The same shim goes under all six liners, colour marking upwards and visible, tongues in the groove. Final check: the difference between two adjacent liners must not exceed 0.04 mm; with new liners, rotate or swap them before changing shim. Volvo B27 / B28 engine reconditioning booklet, pages 3, 40 and 41.
They are the same families, and the comparison is instructive. Volvo identifies four shims by paint and quotes ranges: blue 0.070-0.105 · white 0.085-0.120 · red 0.105-0.140 · yellow 0.130-0.165 mm. DeLorean identifies the same four colours by a tag and quotes a single value: blue 0.087 · white 0.102 · red 0.122 · yellow 0.147 mm — each falling exactly in the middle of the matching Volvo range. Same part, two ways of writing it. The Eagle offers only three, in steel and a step thicker: red 0.10 · silver 0.12 · blue 0.15 mm. And the first two aim at the same protrusion, 0.16 to 0.23 mm, to be taken “as close to 0.23 as possible” — while the Eagle, depending on its build, aims at 0.13-0.20 or 0.05-0.12. Three manuals, one principle: you do not machine anything, you shim. Volvo B27 / B28 engine reconditioning booklet, pages 3 and 41; DeLorean workshop manual, folio C:06:02; Eagle overhaul book, page 46.
With an 8 mm drill and the rear plug in the block — a trick found nowhere else in the Library. Remove the plug, bring the cylinder 1 TDC mark against the 20° mark on the scale, then “insert an 8 mm drill in the blanking plug hole so that it rests on the crankshaft counterweight; pressing lightly on the drill, turn the crankshaft slowly in its normal direction until the drill drops into the hole in the counterweight. The engine is now exactly at TDC for cylinder 1”. That is how the timing scale is checked — and corrected — its zero having to align precisely with the pulley mark. The pulley carries two marks: 1 = TDC cylinder 1, 2 = TDC cylinder 6. The plug goes back with a new seal, at 35-40 N·m. Volvo B27 / B28 engine reconditioning booklet, pages 57 and 58.
The booklet gives them a full page, headed “Do not repair these threads”: the oil filter thread, the connecting rod bolts, certain threads in the cylinder block and the timing gear case, the adjustment screws, the idle adjustment screw in the lower section of the metering unit (B27E 1979-, B28E, B27/28F), the intake manifold's idle screw, and “all conical threads such as plugs and nipples in the intake manifold”. Everywhere else, repair by thread insert is provided for and tooled, with one golden rule: the insert must be screwed in until its top thread is at least half a thread below the working surface, and never to the bottom, or the tang cannot be broken off. The spark plug is a special case: with the head removed, tap from the inside so as not to damage the seat, do not drill, merely re-cut the existing thread — and the bore must not be threaded along its entire length. Volvo B27 / B28 engine reconditioning booklet, pages 15 to 18.
No: there are two types, depending on the thread length tapped into the block. The early type has 30 mm of thread and is fitted without a washer; the late type has 27 mm and is fitted with a washer. The cut-off is read from the engine number: B27A up to 11374 / from 11375 · B27E and B27F up to 57276 / from 57277 · all B28s late type. And the practical consequence matters: “only late type bolts are available as spare parts. If late type bolts are used on early type cylinder heads, washers must be used” — the same washers as for late type bolts. A late bolt fitted without its washer in an early block means three millimetres of thread too many bottoming in the hole: the angle tightening becomes false and the aluminium thread suffers. Volvo B27 / B28 engine reconditioning booklet, page 53.
Hot, and the manual supplies a makeshift thermometer: heat the new ring gear to about 230 °C and check the temperature with “solder of 40% tin and 60% lead, which melts at 220-230 °C”. To remove the old one, drill a hole 10 mm across and 9 mm deep between two cogs — and the warning counts: “do not drill into the flywheel, it may become out of balance” — then split the ring above the hole and lever it off. On fitting, one orientation point: “the bevelled side of the ring gear must face the flywheel”; tap it home if needed with a brass drift and leave it to cool. A side detail: a new flywheel comes rustproofed and must be degreased before assembly, and its bolts are always new, torqued to 45-50 N·m. Volvo B27 / B28 engine reconditioning booklet, pages 36 and 37.
To obtain the necessary interference without forcing the aluminium: expand the head and contract the part. For a guide: head heated to 150 °C, guide chilled to -70 °C with liquid carbon dioxide, and “this must be done very quickly, within 3-4 seconds”, the head laid on a slope so the guides stand vertical. For a seat: head at 100 °C, seat at -70 °C, same time constraint. The target interference is specified: “the valve seat must be 0.070 to 0.134 mm larger than the recess in the cylinder head” — too small means a new head; too large, machine the seat to size. Gloves and safety glasses compulsory. And in both cases an order of work: “valve guides must always be renewed before replacing seats”, then seats milled and valves ground in. Volvo B27 / B28 engine reconditioning booklet, pages 9, 47 to 50.
No: “late type chain tensioners may only be used with late type chain dampers”, and early parts must in any case be replaced by the new ones. Three signs tell them apart: the early bent damper has no oilway, the late one has; the tensioner's orifice goes from 0.4 to 1.2 mm; the straight damper goes from 174 to 220 mm long. An extra trap on B27s built up to mid-1976: their bent damper has a small mounting, and changing to the late type calls for new screws, washers and spacers plus machining two faces of the timing gear case — one to be ground down 5 mm, the other flush — to make room for the wider dampers. One last instruction, the same as at Eagle: “do not disassemble the tensioners; if the locking pin falls out, the complete tensioner must be replaced”. Volvo B27 / B28 engine reconditioning booklet, page 35.
It depends on the model year, and the gap is considerable: 160 to 180 N·m up to 1977, 240 to 280 N·m from 1978. The manual warns as much: “there are two different types of nut” — told apart by the spanner, 36 mm for one, 45 mm for the other. It is precisely that 160-180 N·m figure which, shifted by one line in the maintenance manual's table, made an absurd big-end torque look plausible: the true rod figure is 45 to 50 N·m, with new nuts. Two precautions recur on every page of removal and refitting: lock the flywheel with the locking sector, and above all make sure the pulley key points upwards — “otherwise it will drop into the crankcase”. Volvo B27 / B28 engine reconditioning booklet, pages 10, 21 and 57.
With thrust half washers in four thicknesses — standard 2.30-2.35, then 2.40-2.45 · 2.45-2.50 · 2.50-2.55 mm — for an end float of 0.070 to 0.270 mm measured on a dial gauge. They are, to the hundredth, the same four thicknesses as on the DeLorean. The Volvo peculiarity lies elsewhere: the crankshaft's thrust face itself exists in four widths — standard 29.20-29.25 mm, then 29.40-29.45 · 29.50-29.55 · 29.60-29.65 — meaning the face can be re-machined wider and taken up with thicker washers, instead of scrapping the crankshaft. The washers go in with their oil grooves facing the crank web, and the manual insists on the two lower segments, whose oilways must be respected. Volvo B27 / B28 engine reconditioning booklet, pages 9, 38 and 39.
For the same reason as on the DeLorean and the Eagle: “the crankcase and cylinder block must be flush, otherwise distortions may result and cause noise or damage”. Align it with a straight edge, rear of the casing level with the rear of the block, on both sides, nuts finger tight only — then torque to 30 N·m in sequence, check the alignment again, and only then go to the mains' angle tightening (slacken nut 1, 30-35 N·m, 73-77°, then the others one at a time). Two fitting details go with it: the casing and cap faces take a sealer (P/N 1161058-1), and the gearbox guide pins must protrude 10 to 12 mm — the original tubular pins are replaced by solid ones, with locking fluid. Volvo B27 / B28 engine reconditioning booklet, pages 29, 43 and 44.
The dimensions say it better than any argument. The connecting rod measures 146.15 mm between centres at Volvo as at Eagle. The new cylinder head stands 111.07 mm tall at Volvo as at DeLorean — and all three manuals, plus the Alpine guide, forbid machining it. The crankshaft thrust washers come in the same four thicknesses at Volvo and DeLorean (2.30 · 2.40 · 2.45 · 2.50 mm), and the target end float is identical, 0.07 to 0.27 mm. The main journal repair size is the same at Volvo (69.743-69.762) and DeLorean (69.762), that is 0.300 mm under the original 70.062 — Eagle included, whose manual gives 70.043-70.062 as standard. The piston pin is shrunk at 250 °C in all three books, with a piece of solder for a thermometer at Volvo and at Eagle. And the rod side clearance is 0.20 to 0.38 mm everywhere. The PRV is not an engine with variants: it is the same engine, documented in three workshop languages. Volvo B27 / B28 engine reconditioning booklet, pages 5, 9 and 10; DeLorean workshop manual, folios C:02:04 to C:02:06; Eagle overhaul book, pages 6 and 7.
Its vintage: “two types are in use — the early one without filter, the late one with filter. Early type valves must be replaced with the new type”. It is an overhaul point you never see, buried in the block near the oil filter. Replacing it calls for two precautions: “take care not to damage the oil filter mating surfaces and make sure that dirt does not enter the oilways”; the new valve goes in spring facing inwards, and the washer is secured by making three notches in the block with a drift. In the same vein, two more traps from that chapter: the late type lower crankcase has a collar that stops the oil channel sleeve dropping into the sump — on an early casing, fit a new sleeve with locking fluid. Volvo B27 / B28 engine reconditioning booklet, pages 30 and 43.
Yes, and the manual boxes the warning. Engine types 498354 and 498356 up to and including engine no. 7630, plus exchange engine 1218098, “may be equipped with early type crankshafts and connecting rods” — and only parts of the same type may be used together. Before ordering a crankshaft or a set of rods for an early B27E, it is the engine number you must read, not the year. Volvo reconditioning booklet, page 32.
Three drawings, depending on era and valve. Intake, early types: seat width 1.7 to 2.1 mm, 30° angle. Intake, late types — the so-called “venturi” seat: a narrower 1.3 to 1.7 mm width, obtained with two correction angles of 15° and 60°. Exhaust: width 2.0 to 2.4 mm, 45° angle. The manual also states, when replacing a seat, that the interference between the seat and its bore in the head must be 0.070 to 0.134 mm, and that the rocker arm's contact face against the camshaft is surface-hardened and must not be ground. Volvo service manual, section 2, pages 6 to 8.
No — and that sets it apart from every other PRV in the Library. The 3.0L has a hydraulic tappet housed inside the rocker arm itself (an “automatic lash adjuster”, one per rocker, in left and right versions): take-up is automatic, there is no adjusting screw. The Alpine A310, the DeLorean and the Volvo B27/B28 are all screw-adjusted. The practical consequence: valve clatter on a 3.0L is not taken up, it is diagnosed — oil level, oil too thin or diluted, worn rockers or shafts, a failing hydraulic tappet. This also sheds light on an open question about the Z7X family, whose Renault manual mentions hydraulic tappets: this Z7X 711 does have them. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-10, 9-38 and 9-39.
Three checks, all by eye and straight edge. The bottom of the tappet must be crowned: against a straight edge, if it looks flat or dished, replace it. The rocker's cam follower pad must be crowned too: if flat, replace the rocker and check the matching cam lobe, which will have worn it. And the rocker's oil squirt hole must not be blocked — it is what sprays the lobe; clear it with compressed air. A reassembly detail: the thrust washer goes in with its slots facing the tappet, and the rocker shaft only fits one way — it has two holes at one end, the larger one at the top, which lines up with the set bolt. The oil galley plugs at the ends of the shaft are pressed in and not replaceable. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-38 and 9-39.
No, and the difference shows at a glance: on the left camshaft, both lobes for a given cylinder are on the same side; on the right, they are on opposite sides. They are removed and refitted from the rear of the cylinder head, once it is off, by freeing the retainer from its groove. On assembly the journals are lubricated with Jeep/Eagle Super Oil Conditioner and the retainer bolt torqued to 12 N·m. A camshaft with worn lobes is replaced — but look for the cause on the rocker and lubrication side first, or the new one will wear like the old. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-40.
By bringing the keyway slot straight up before pulling the pulley: “the key could fall out of the crankshaft if the pulley is removed with the keyway facing down”. If it does not point up, turn the crankshaft until it does. Another precaution specific to this nut: it is fitted with thread lock, so “use a BRASS hammer and strike the nut prior to loosening”. On reassembly, Loctite 271 on the threads and 180 N·m. The same key worry appears at Volvo, which asks you to turn the crankshaft to 20° BTDC before removing its pulley. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-42 and 9-43.
It depends on their condition, and that is the subtlety. New, the two chains are identical and can go on either camshaft sprocket; used, they MUST go back on the side they came from. Same rule for tensioners, shoes and guides: identical when new, back on the same side once used. The camshaft sprockets are never identical: the right one has a spacer, the left one does not. Hence the manual's instruction: on dismantling, keep left and right separate and do not mix them. Wear check: measure the chain gap with a drill bit — if the solid end of the bit does not fit into the gap, the wear is not excessive and the parts can be reused. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-48 and 9-49.
The left bank is timed first. On the left camshaft sprocket, align the UNPAINTED link between the two painted links with the sprocket's stamped mark. At the crankshaft the mark is on the middle sprocket (the RIGHT chain's): place the single painted link of the LEFT chain on the tooth directly behind the one carrying that mark. Guides and tensioners are torqued to 6 N·m, camshaft sprocket bolts to 80 N·m. ⚠️ For checking, one crucial rule: “once the crankshaft is rotated, the paint marks on the chains will not align with the marks on the sprockets. What is checked is the position of the timing marks IN RELATION TO ONE ANOTHER, not the position of the paint marks”. Turn the crankshaft 180°: right sprocket and crankshaft marks aligned; then another 90°: left sprocket and crankshaft marks aligned. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-49 to 9-53.
Remove its lock. The manual says it twice: the lock must be set in the locked position before removal, and “the timing chain tensioner lock should not be removed. The lock is held in place by a spring that pushes a steel ball against the lock finger. If the lock is removed accidentally, replace the tensioner assembly, because there is no way of checking the position of the lock finger in relation to the steel ball”. To fit a tensioner, turn the ratchet anticlockwise with a thin screwdriver, push the arm in, position the tensioner over its filter and the shoe into the arm. And once everything is assembled, push both shoes in to release the ratchets, then let them out. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-48, 9-51 and 9-52.
Two things, and the second one catches restorers out. Never flush it — radiator or whole system — with caustic soda or any alkaline cleaner: the light alloy corrodes and the system starts leaking. And never leave a removed radiator lying open for more than 48 hours. Beyond that, particles left at the brazed joints during manufacture, together with chloride-bearing water residues, oxidise the alloy on contact with air and make the radiator leak. After 48 hours the manual gives two options and no third: either rinse it with water, blow it out with compressed air and plug every opening, or leave it full of coolant. Light-alloy cores also make a suitable coolant compulsory — the manual names Glaceol AL type C. The Safrane's manual gives the same rules — no caustic soda or alkaline products, 48 hours, rinse-blow-plug or keep full — and adds why after 48 hours: brazing particles left from manufacture and chlorides from the old coolant start oxidising the aluminium once exposed to air. Alpine M.R.297, folio 19-5 · Safrane M.R.302, chapter 19.
Because of what happens after the ignition goes off, and the manual spells it out: “if the engine is not idled for about 30 seconds, or if the engine is revved before the ignition is turned off, the turbo charger will continue to turn under inertia (engine stopped), which may damage the turbo charger shaft”. Engine stopped means oil pump stopped: the shaft is still spinning, and nothing is feeding its bearings. Thirty seconds of idling brings the turbo's speed down before the supply stops — which is the same problem the Alpine A610 and the catalysed R25 V6 Turbo solve mechanically, with an electric water pump running on for twelve minutes after switch-off. The same page carries a second warning, about the oil filter: two boss threads exist, 20 × 1.50 and 19 × 1.587 (3/4 inch, 16 TPI), and a 20 × 1.50 filter can be wrongly screwed onto a 19 × 1.587 boss — where it will work loose under vibration. The play is obvious before the filter is offered up to the block, which is the moment to notice it. Safrane M.R.302, chapter 10.
Because a paint booth bakes, and the manual sets the limit: “at a temperature above 80 °C — for instance in paint booths — remove the enrichment, idle and ignition computers”. Three computers, all of which a full respray would cook in place. The same page lists three precautions that apply every day, not just in the body shop: never disconnect or connect any part with the ignition on; disconnect the battery before charging it; and a behaviour to know before diagnosing a “dead” pump — with the engine stopped and the ignition on, the fuel pump must not run, because its circuit passes through the control relay, which is energised only when the starter is engaged. A pump that stays silent with the key at the ignition position is working exactly as designed. And before any fuel system check, the manual asks you to rule out three things: another cause entirely (plugs, distributor, advance), an air leak between airflow meter and inlet valve or in the exhaust between exhaust valve and converter, and fuel not actually reaching the injectors. M.R.249, NT 1205 E supplement, page 32.
The B 29 A, six-cylinder, in the German edition of July 1986 — cars intended for Germany, Austria and Switzerland. Its features, as the cover lists them: Z7W V6 engine; K(E)-Jetronic injection with mixture control by oxygen (lambda) sensor; an exhaust with a three-way catalytic converter; running on unleaded petrol of octane rating 92; a remote air filter; and a modified crankcase breathing circuit. Anything the supplement does not cover is to be found in M.R.249 with its special instructions and technical notes — “in particular no. 1150”, the note on the 1986 idle regulation — in the Mot. Z engine manual, the INJ. K (E) injection manual and the Renault 25 wiring diagrams. M.R.249, NT 1205 E supplement, page 2.
Twelve symptoms across the top, causes down the side, a dot where they meet — and a note first: the table assumes the engine is in good condition and the electrical equipment has been checked and repaired. The symptoms: 1 won't start or starts badly · 2 starts then stops · 3 irregular idle · 4 poor acceleration · 5 misfires at every speed · 6 excessive fuel consumption · 7 lack of power · 8 idle CO too high (above 0.5 %) · 9 tailpipe CO = CO before the catalyst · 10 pinking · 11 idle too high · 12 idle too low (engine stalls). Read by cause, with the remedy the table gives: injection relay (1, 2) — check its supply · electric fuel pump not running (1) — fuel pressure; relay and pump powered? if so, replace the pump · idle switch misadjusted or faulty (3, 11) — check the setting or replace · air leak in the intake (1, 3, 11) — manifold, its components and every hose · supply system (1, 6, 7) — supply pressure, injector tightness and calibration · fuel pressure too low or none (1, 7, 10) — pressure, filter, lines, regulator · fuel pressure too high (6) — return line blocked or pinched, regulator faulty · idle regulation not working (1, 3, 11, 12) — the valve, the coolant sensor, the 60 °C thermal switch, the idle switch · idle valve supply fault (1, 11, 12) — wiring and computer conformity · vacuum advance control (4, 6, 7) — pneumatic circuit, solenoid valve, idle switch · ignition, engine too hot, wrong mixture, unsuitable fuel (7, 10) — cooling, ignition, supply, full-load switch, mixture control. On the second page: idle or mixture regulation system (3, 5, 6) — integrator voltage, valves and components · mixture regulation (6, 8) — integrator voltage, oxygen sensor · full-load switch (4, 7) — replace if needed · idle switch, oxygen sensor, fuel pressure (3, 8) · cold start system (1, 2) — cold start injector, its circuit, the thermo-time switch · 15 °C thermal switch, supply pressure (1) — below 15 °C, the 15° switch is faulty · ignition computer (1) — its supply and the coil resistance · thermo-time switch, pressure regulator (2, 7) · mixture regulation, catalyst (9) — integrator voltage; test the fuel for lead · throttle not closing (3) — free it, adjust the pedal linkage and the throttle · throttle not opening fully (7) — adjust the pedal control · harness and connectors disconnected and the electronic computers (ignition, speed and mixture regulation) (1 to 7, 11, 12) — and before replacing a computer, a complete check of the electrical circuits. M.R.249, NT 1205 E supplement, pages 64 and 65.
Not the same depth on both sides: intake guides go in until their bottom is 30 mm from the top of the seat, exhaust ones 26 mm. Then ream to 8 mm — and the manual insists: “to ensure proper sealing between valve and seats, the seats must be ground AFTER a new guide has been installed and reamed to 8 mm”. Finally, clean the head of all metal chips and grinding dust. The pre-assembly check needs no tool: slide each valve into its guide slowly — it must slide without drag; if drag is felt, check both guide and stem. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-37.
By going back to the cause, and that is what makes its diagnosis chart valuable for a wet-liner engine. Against low compression it lists among the possible causes: “blown cylinder head gasket — could be caused by improper liner protrusion, warped cylinder head”, and the matching correction is not “replace the gasket” but “replace the gasket and check liner protrusion, cylinder head warpage”. The same appears under overheating. In other words, a head gasket that fails twice on a PRV is not a poor-quality gasket: it is a liner protrusion to be reset. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-9 and 9-10.
Yes, and it is written in the diagnosis chart: among the twelve causes of overheating on the 3.0L is “anti-freeze concentration too high”, whose correction is simply “correct concentration level”. Water carries heat away better than neat glycol; beyond a certain mix you lose in cooling what you gain in frost protection. The cooling chapter puts it another way: “richer mixtures cannot be measured with normal field equipment and can cause problems associated with 100 percent ethylene-glycol”. Volvo holds the same line from the other side: 50/50, and never water alone — because on an all-aluminium engine it is the corrosion inhibitor that protects. 1990 Eagle service manual, folios 9-8, 9-10 and 7-10; Volvo manual, section 2, page 12.
Eight causes, in order: low oil level · clogged filter or supply/return lines · worn oil pump gears or body bores · excessive tappet-to-bore clearance · relief valve stuck open · thin or diluted oil · excessive bearing clearance (camshaft, connecting rod or mains) · loose oil galley plug. Two corrections are worth knowing before stripping anything: if the camshaft bearings are worn, it is the cylinder head that must be replaced — they are line-bored into it; and if the pump's gear-to-case clearance is excessive, it is the cylinder block that must be changed, the pump being housed in it. Conversely, pressure too high has only one cause: the relief valve stuck closed. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-7 and 9-9.
A fully charged battery and a healthy starter first — “otherwise the indicated compression pressures may not be valid for diagnosis purposes”. Then: clean the spark plug recesses with compressed air before removing the plugs (so no dirt falls into the cylinder), secure the throttle wide open, fit the gauge and turn the engine on the starter for three revolutions — record the pressure on the third, and repeat for each cylinder. Compare with the Volvo method, which asks the same but also specifies the cranking speed: 250 to 300 rpm, for 8 to 11 bar. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-5.
It is a two-piece assembly pinned together, indexed to the left camshaft, running in a seal housed in the timing cover, behind the distributor housing. The rotor is attached to the front of that drive. Consequence: to replace that seal — a classic oil leak there — you must remove the timing cover, separate the drive's two sections (tapping a small drift at the parting line if needed) and remove the distributor housing. The new seal goes in with tool 6126, flush with the cover. Torques worth knowing: rotor bolts 3 N·m, distributor cap bolts 4 N·m, distributor drive / left camshaft sprocket bolt 80 N·m. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-43 to 9-46.
The manual names several, scattered through the procedures. The oil pump inlet tube O-ring: “never reuse the inlet tube O-ring seal. Always install a new seal”. The oil pan gasket, which goes on dry — no sealer — and whose residue is scraped with a wooden or plastic scraper, never metal, which would score the casing. The manifold gaskets, intake and exhaust, and the timing cover gasket, whose tabs are cut flush with the head after fitting. On the oil pump relief valve, a direction to respect: the open end must face the spring — and never strike the cylindrical part that contains it. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-43, 9-47 and 9-54.
A 90° V6 of 3.0 litres (182 cubic inches), bore × stroke 93 × 73 mm, compression ratio 9.3 : 1, rated at 232 N·m at 3,750 rpm, firing order 1-6-3-5-2-4. Cylinder block and heads in aluminium alloy, steel camshaft, cast nodular iron connecting rods, hemispherical combustion cavity in the piston. The crankshaft is forged steel with a 30° journal offset — this is the split-crankpin version of the PRV. Capacities: 5.7 litres of oil, 8.2 litres of coolant. Cylinders are numbered 1 to 3 rear to front on the left bank, 4 to 6 on the right. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-1 and 9-2.
Yes, and the Chrysler training book writes it plainly at the head of its general specifications: ENGINE TYPE Z7X, ENGINE SUFFIX 711. The American PRV is therefore a Z7X 711 — the same family as the Alpine A610's Z7X-744 and the Safrane Bi-Turbo's Z7X 726. The identification tag is attached to the right-hand side of the block, below the exhaust manifold: the first six characters give the type (Z7X711), the second row the build sequence. Cars assembled for Tennessee carry an extra number stamped behind the right-hand engine mount bracket, framed by asterisks to prevent alteration. Chrysler “Premier/Monaco 3.0 liter Engine Overhaul” book, page 3.
2,975 cc — 180 cubic inches —, 93 mm bore, 73 mm stroke, 9.3 compression ratio. Exactly the capacity of the A610's Z7X-744 and the 605 and XM's ZPJ. Power: 150 hp at 5,000 rpm, torque 232 N·m (171 ft-lbs) at 3,750. ⚠️ Note that the two Chrysler documents do not give the same capacity: the service manual writes “3.0 LITER (182 CU. INCH)” at folio 9-2, the overhaul book “180 CU. IN. (2975 cc)”. Arithmetic settles it — 93 × 73 over six cylinders is indeed 2,975 cc, that is 181.6 cubic inches. Chrysler overhaul book, page 3; 1990 service manual, folio 9-2.
No — and it is a boxed caution in the overhaul book: “do not remove and install the cylinder head with the exhaust manifold attached to it. This will damage the tabs on the cylinder head gasket during installation”. On the same page, two other easily missed points: the head gaskets are not interchangeable between right and left — the same remark as on the Alpine A310 — and a thin bead of RTV goes where the head gasket meets the timing case cover gasket. The camshaft thrust plate bolt is tightened to just 5 N·m. Chrysler overhaul book, pages 19 to 22.
On two, worth knowing before tightening or diagnosing. Spark plugs: the service manual gives 15 N·m at folio 8D-18, the overhaul book 22 N·m (16 ft-lbs). Oil pressure: the service manual quotes 414 kPa (60 psi) at 4,000 rpm at folio 9-69, the overhaul book 60 psi at 5,500 rpm — the two do agree on idle, 1 bar at 790 rpm, thermostat open and coolant at 89 °C. Add the capacity discrepancy already noted. Three divergences within one manufacturer's own corpus: which is why the Library publishes both documents rather than one. 1990 service manual, folios 8D-18 and 9-69; Chrysler overhaul book, pages 3 and 20.
No, and the way the manual writes it says so by itself: a single column of figures, where the A310 guide gave two, one per bank. Intake opens 14° BTDC, closes 58° ABDC; exhaust opens 56° BBDC, closes 12° ATDC; overlap 26°, intake duration 252°, exhaust duration 248°. This follows from the 30° journal offset: firing intervals became even, and both banks share one diagram. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-68.
Nothing like the French method — and there are two procedures, which only the Chrysler overhaul book distinguishes: the service manual gives just one. In both cases, pre-tighten all bolts to 60 N·m in sequence, starting at no. 1, then work bolt by bolt with the graduated disc (tool 7321). Engines up to and including no. 89615: slacken completely, tighten to 20 N·m, then 106° ± 2°. Engines from no. 89616: slacken completely, tighten to 40 N·m, then 180° (+0, −20). The number is on the identification tag, right-hand side of the block, below the exhaust manifold. The manual also gives a verification torque of 70 N·m. Two warnings worth the detour: never use an air impact gun on the head bolts — the aluminium block's threads will not survive — and do not lift the head straight up, or the liners come out of the block with it; drive the dowels down below the gasket first, with an old push rod. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-32 and 9-71.
Protrusion must fall between 0.05 and 0.12 mm, with a maximum difference of 0.04 mm between two adjacent liners — and it must step down: greatest at position no. 1 (left bank) and no. 4 (right bank), smallest at no. 3 and no. 6. You get there by changing the base seal thickness, identified by tabs: red 0.10 mm, silver 0.12, blue 0.15. ⚠️ Never transpose from another PRV. The Alpine A310 and the DeLorean DMC-12 share a different set of seals — blue 0.087 · white 0.102 · red 0.122 · yellow 0.147 mm — for a target protrusion of 0.16 to 0.23 mm. Blue is the THINNEST there, where it is the THICKEST here. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-64, 9-68 and 9-69.
Main journals 70.043 to 70.062 mm — exactly those of the Alpine A310's V6 of 1977, thirteen years earlier. The crankpins, however, have grown to 59.971 to 59.990 mm, against 52.267 to 52.286 on the A310: this is the 60 mm crankpin the Renault Z engines manual refers to as “⌀ 60 mm or 52.290 depending on type”. Main bearing clearance 0.038 to 0.089 mm, end float 0.07 to 0.27 mm (the A310 figure again), main bearing bore in the block 74.000 to 74.019 mm. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-68.
101 kPa (14.7 psi) at idle, at 790 rpm, and 414 kPa (60 psi) at 4,000 rpm — roughly 1 and 4.1 bar. The manual states the condition: check only with the thermostat open and coolant at 89 °C. ⚠️ One bar at idle on this engine, where the Alpine A310 guide asks for two at 800 rpm: two engines of the same family, two figures, and neither applies to the other. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-69.
Not this one either. The manual gives a maximum warpage of 0.051 mm and states “NOT RESURFACEABLE” — the same prohibition as the Alpine A310 guide, thirteen years earlier and from another manufacturer. The related figures: head height 110.83 mm (110.87 ± 0.15 on the A310: it is the same head), chamber volume 50.6 cc, head gasket thickness 1.45 mm, valve guides 8.0 mm ID and 13.0 mm OD (13.35 repair), length 45 mm intake and 49 mm exhaust. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-68.
From the bottom of the liner, and the manual says why: the top of the liner is not chamfered — pushing the piston in from there damages the rings and ring lands. Ring gaps are spaced 120° apart and are not to be trimmed: they are pre-set to the liner. Fitting direction differs between banks: on the left (1, 2, 3) the piston arrow faces the crankshaft pulley end and the rod shoulder the flywheel end; on the right (4, 5, 6) both face the pulley end. Two precautions: slide pieces of rubber hose over the rod bolts so they cannot nick the journals, and hold the liners already fitted with the 7315 clamps. The piston pin is an interference fit in the rod: heat the small end on a 1,500 W hot plate until the bore expands. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-64 and 9-67.
In N·m: crankshaft pulley nut 180 · camshaft sprocket bolt 80 · camshaft thrust plate 12 · cylinder head bolt, verification torque 70 · head cover 12, rear head cover 6 · rocker shaft lock bolt 6 · timing case cover 12 · chain guide 6 · chain tensioner 6, tensioner shoe 12 · crankshaft rear seal housing 12 · oil pan 12, drain plug 30 · oil pump: cover 12, sprocket 6, sump to block 12 · alternator: locking bolt 27, pivot 50 · A/C compressor 27 · starter motor 42 · engine mount 65 · engine cradle 125 · transaxle 65 · torque converter to drive plate 33. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-71 and 9-72.
The manual gives the table. Jeep/Eagle Gasket-in-a-Tube: block-to-lower-casing mating faces, and block-to-timing-cover below the gasket at the head covers. Loctite 242: camshaft cover plate bolts at the rear of the head, and the four bottom bolts of the front cover. Loctite 271: crankshaft pulley nut, oil filter adapter, oil pump sprocket bolts. Loctite 277: cylinder head freeze plugs, block oil gallery plugs, rocker shaft plugs. Loctite 592: the timing cover pipe plug, the one giving access to the right camshaft sprocket bolt. Super Oil Conditioner: rocker arm pads and camshaft journals on reassembly. Note that the crankshaft pulley and the oil pump sprocket are the same two places the A310 guide calls for Loctite. 1990 Eagle Premier / Dodge Monaco service manual, folio 9-72.
On two points, and it is better to know before tightening. The connecting rod nut: the reassembly procedure says 42 N·m (31 ft-lbs) at folio 9-67, the torque table says 47.5 N·m (35 ft-lbs) at folio 9-71. Both are internally consistent in their own unit: this is a genuine disagreement between two pages, not a conversion slip. Rod twist and bend, on the other hand, really are a faulty conversion: folio 9-68 quotes 0.075 mm / 0.002 in and 0.080 mm / 0.003 in, when 0.002 inch is 0.051 mm and 0.003 inch is 0.076 mm — which is exactly what folio 9-64 gives, and those are the figures to keep. 1990 Eagle Premier / Dodge Monaco service manual, folios 9-64, 9-67, 9-68 and 9-71.
Not by the wastegates alone. The two KKK K04 turbos do have a pressure-limiting valve with a set point, but it is the ECU that commands the pressure, by creating a leak in the pneumatic circuit shared by both wastegates, through a solenoid — the SEM valve. Safrane Bi-Turbo manual, folios 12-4 to 12-7.
The manual gives the setting via the rod travel: 430 ± 30 mbar for 0.43 ± 0.05 mm of travel, and 550 ± 30 mbar for 3 ± 0.05 mm. Manifold pressure measured on the XR25: 1,500 ± 25 mbar between 2,400 and 2,600 rpm. Bypass valve: opening vacuum 200 − 20 mbar. Safrane Bi-Turbo manual, folio 12-7.
A ⌀ 2.5 mm restrictor on the manifold line, driven by a 12 Hz duty cycle. The ECU starts from a base map — the memorised nominal pressure — then corrects the valve’s opening duty cycle against the manifold pressure it reads. XR25 readings: #20 for the learnt value, #11 for the commanded duty cycle. Safrane Bi-Turbo manual, folio 12-7.
The front one, yes — provided the turbo outlet elbow is removed, and provided you refit the locking clip on the regulator rod. The rear one, no: it can only be adjusted with the turbo removed, and its opening pressure cannot be checked directly. Through the right front wheel arch you can only confirm that the wastegate is fed and that the rod moves. Safrane Bi-Turbo manual, folio 12-11.
Because the front subframe has to come down: the manual goes straight on to give the torques for the anti-roll bar ball joints (4), the steering ball joints (4) and the lower ball joints (6.5 daN.m). It is not a turbo removal, it is a front-end removal. Safrane Bi-Turbo manual, folio 12-18.
The same front and rear: turbo-to-manifold nuts 2.5 · outlet elbow nuts 2.5 · water unions 4 · oil unions 2 top and 1 bottom · wastegate rod locknut 0.8 daN.m. Safrane Bi-Turbo manual, folios 12-14 and 12-18.
For the turbo bearings. With the engine running, water flows from the block to the pump and on to the radiator outlet. With the engine stopped, during the delay that follows switching off, the electric pump reverses the flow and pushes water through the turbos — which is what stops them cooking after shutdown. Safrane Bi-Turbo manual, folio 18-7.
With the ignition off, if the thermal switch goes above 102 °C, a timed relay runs the cooling fans at half speed until the temperature drops back below the threshold (92 °C). Safrane Bi-Turbo manual, folio 18-1.
6.2 litres at an oil change, plus 0.5 litre if the filter is renewed. Grades by climate: CCMC-G4 15W50, CCMC-G5 10W50 or 5W40/5W50 in the EEC; API SG 15W40, 10W40, 10W30 or 5W30 elsewhere. Safrane Bi-Turbo manual, folio 04-1.
PK9 gearbox: 2.1 l min to 2.6 l max (0.25 l for the filter), ELF Tranself TRZ 75W80 (API GL5 or MIL L2105 C/D). OT2 final drive: 1.3 l. Cooling: 10 l of Glacéol, protected to −23 °C, or −40 °C in the cold-climate version. Tank: about 76 l, unleaded. Power steering: separate 1.1 l reservoir (ELF Renault Matic D2 or Mobil ATF 220). ABS brakes: 1 l, SAE J1703 and DOT 3. Safrane Bi-Turbo manual, folios 04-1 and 04-7.
Every 20,000 km. Bosch plugs. Safrane Bi-Turbo manual, folio 12-7.
7½ × 17 wheels, 44 mm offset, 225/45 ZR 17 tubeless tyres, wheel nuts to 10 daN.m. The manual gives only one pressure, and it is the motorway figure: 2.5 bar front, 2.3 bar rear. Check them cold — driving adds 0.2 to 0.3 bar, which must never be let out. On four-wheel drive, the four tyres must wear at much the same rate. Safrane Bi-Turbo manual, folio 35-1.
A Siemens unit, Siemens no. S101 722 103, homologation 77 00 860 304, Renault part 77 01 038 468 — XR25 diagnostic code 244.3. Safrane Bi-Turbo manual, folio 12-7.
A heated sensor, brought to 850 °C. Lean mixture: 0 to 80 mV; rich above that. Evaporative control with a Rochester canister. Safrane Bi-Turbo manual, folio 12-7.
Not with a gauge: with a multimeter, on the pressure sender. Resistance varies inversely with pressure — disconnect the connector, fit extension Mot. 843 and a multimeter between sender and earth. Safrane Bi-Turbo manual, folio 10-7.
A PK9, with ELF Tranself TRZ 75W80 oil. Safrane Bi-Turbo manual, folio 21-1.
In three ways, depending on what the engine is doing. Off boost, vacuum acts on a ⌀ 1.7 mm jet downstream of the throttle, through a non-return valve. On boost, that valve closes the downstream circuit and everything then depends on engine speed: at low revs and full load, the vacuum at the compressor inlet is not enough and the vapours go through the vacuum capsule; at high revs and full load, it is enough and recycling happens through the ⌀ 6.5 mm jet, upstream of the front compressor. Safrane Bi-Turbo manual, folios 14-1 and 14-2.
To purge the canister while on boost. In those phases, manifold pressure makes normal fuel-vapour recycling impossible, so the vapours are allowed back to the turbocharger inlet instead. A flexible steel reed lifts under sufficient vacuum, comes to rest against a stop bar and opens the air passages. Safrane Bi-Turbo manual, folio 14-4.
The manual describes exactly this symptom: petrol stains on the ground under the right front of the car, or a strong fuel smell, usually mean a canister saturated because it is not being purged. Check: disconnect the line at A and fit a vacuum gauge — the reading must equal manifold vacuum. If not, check the pipe for leaks all the way to the manifold, and that the take-off is clear. Then fit the gauge at B and check for vacuum, engine hot, while blipping the throttle gently with no load. Safrane Bi-Turbo manual, folio 14-7.
Three things, before the analyser is even connected: the ignition (correct plugs, correctly gapped, HT leads sound and properly connected), the injection (correct supply, conformity check with the XR25) and the exhaust line (correct specification and no leaks). The manual also advises asking about the car’s history: running out of fuel, lack of power, wrong fuel. Then warm the car until the cooling fan has cut in twice before connecting a calibrated four-gas analyser. Safrane Bi-Turbo manual, folio 14-8.
With a dedicated detector kit, distributed at the time by NAUDER — reference T900 for the complete kit, T900/1 for a refill of forty test papers. Conditions: engine stopped, exhaust pipes warm but not hot, and never below 0 °C. Wipe the inside of the tailpipe with a dry cloth first. Safrane Bi-Turbo manual, folio 14-9.
A fault acknowledged by Renault, which devoted a yellow Technical Note of October 1997 to it (ref. 77 11 195 529), bound at the end of the manual. The symptom described: “dull cyclic noise from 150 km/h”. Two possible causes: the OT2 final-drive rear mounting incorrectly fitted, or an internal OT2 fault. The allowed times show the gap between them: 3.0 hours to refit the mounting, 8.7 hours to replace the final drive. Safrane Bi-Turbo manual, yellow Technical Note, October 1997.
Yes, and Renault addressed it as early as July 1994 with a blue Technical Note (ref. 77 11 174 069), also bound at the end of the manual. The cause: the high-pressure hose damaged by radiated exhaust heat. The fix, on the production line and in service alike: fitting an aluminium sleeve over the flexible section — part number 77 01 038 416, with two clips. Cars concerned: build range S 000500 to S 000800, to be done at the first workshop visit. Safrane Bi-Turbo manual, blue Technical Note, July 1994.
The ZPJ4 (SKZ): six cylinders, 93 mm bore, 73 mm stroke, 2,975 cc, compression ratio 9.4:1. 147 kW — 200 bhp — at 6,000 rpm, maximum torque 26 mdaN at 3,600 rpm, maximum engine speed 6,500 rpm. Unleaded RON 95. Citroën Technical Note no. 23, XM V6.24, page 3.
Light alloy, four bearings, one overhead camshaft per head driven by a chain with a mechanically reset hydraulic tensioner. Four valves per cylinder, operated through intermediate followers by hydraulic tappets housed in the rockers. A support plate carries two rocker shafts: one for the intake, with separate rockers — six per head —, one for the exhaust, with one-piece rockers — three per head. The front head also carries the balance shaft. Citroën Technical Note no. 23, XM V6.24, page 5.
No, and the Technical Note says so in capitals: “WARNING: the centre followers are different”. Intake: 41.32 mm long. Exhaust: 40.12 mm. Just over a millimetre apart, invisible to the eye, between two parts that look alike. Citroën Technical Note no. 23, XM V6.24, page 5.
Specific 62-link chains, instead of 64 on the ZPJ, and a guide arrangement unique to this engine. Timing is set on the marks, at one turn plus 240°. Citroën Technical Note no. 23, XM V6.24, page 6.
6.5 litres after a change, 7 litres on a new engine, and 2 litres between the dipstick marks. Recommended oil TOTAL GTI 10W40 or GTS 15W40. Minimum pressure 5.5 bar at 5,500 rpm (at 80 °C), pressure switch set at 0.5 bar. PURFLUX LS 520 C cartridge, renewed every 20,000 km. Citroën Technical Note no. 23, XM V6.24, page 6.
Because its two exhaust runs are not the same length. Each head has its own “6 into 1” pressed-steel manifold with a METEX ball joint, and each bank its own oxygen sensor and catalyst. The front bank’s run being longer, a small light-off catalyst under the engine pre-treats its gases so that both main catalysts work at the same temperature. Citroën Technical Note no. 23, XM V6.24, page 7.
Through three configurations, commanded by two solenoids according to engine speed and throttle position. Engine stopped or idling, neither solenoid is energised: the two half-plenums are separate, one per bank — gas speed is at its highest, this is the torque configuration. Between 4,000 and 5,000 rpm, the long-link solenoid is energised: the volumes communicate, the transition stage. Above 5,000 rpm, both solenoids are energised: the half-plenums are joined into one, the power configuration. Citroën Technical Note no. 23, XM V6.24, pages 12, 13 and 19.
An SBAE FENIX 4, housed in the electronics box on the right front wheel arch, with a 55-way connector. It manages ignition, injection, the ACAV, idle control, oxygen-sensor heating, canister purging and the coded immobiliser. Citroën Technical Note no. 23, XM V6.24, page 14.
No. Idle speed — about 750 rpm — is set by the ECU through the idle solenoid, and the Technical Note is categorical: do not touch the throttle stop screws. What can be adjusted is the synchronisation of the two throttle bodies: remove the siamese pipe between air filter and bodies, slacken screw (1), work the opening linkage until both butterflies move together, then tighten by one further turn. And the drive roller, throttle closed, must turn freely but without play for 3 mm of sector travel. Citroën Technical Note no. 23, XM V6.24, page 27.
The ECU stores faults, permanent and intermittent alike; it is activated with the 4097-T decoder or the SOURIAU 26 A station. ⚠️ Any interruption of the ECU supply erases the stored fault list, resets the adaptive corrections and arms the coded immobiliser. Hence a mandatory order: put the immobiliser in neutral mode, preliminary checks, read the fault codes, connect the breakout box, road test if needed, fault-find, repair, then clear the code. Citroën Technical Note no. 23, XM V6.24, page 22.
The system earths and the connections of each device — fuel pump, ECU, absolute pressure sensor, speed sensor, injectors, battery — and that only the green light on the coded immobiliser keypad is on. Then two simple checks: ignition, with a strobe lamp on a plug lead while cranking, and the fuel circuit, where pressure must read 3 bar. Citroën Technical Note no. 23, XM V6.24, page 23.
No, and it is the most surprising line in the original specifications. Left bank: intake opens 9° BTDC, closes 45° ABDC; exhaust opens 45° BBDC, closes 9° ATDC. Right bank: 7° / 43° / 43° / 7°. The printed table really does carry two separate columns, “Left Bank” and “Right Bank”. SAE paper 760110, page 14 (Appendix I). Library →
At about 0.45 MPa, i.e. 4.5 bar, by a piston discharge valve returning the excess flow to the pump suction side. SAE paper 760110, page 8. Library →
Over 14 litres per 1000 engine rpm, and from as low as 600 crankshaft rpm — in-use output is what dictated the pump's size and speed. A straight gear pump, its housing integrated into the front face of the block, chain-driven without a tensioner at 18/28ths of crankshaft speed: a compromise between size, pressure build-up at low speed and safety against cavitation. SAE paper 760110, pages 7 and 8. Library →
5 to 8 thousandths of a millimetre for the cartridge fitted in production at Douvrin — that is the one protecting the engine during break-in. Cartridges supplied as spare parts have a threshold of 10 to 15 thousandths. A full-flow filter, throw-away paper cartridge, with a by-pass relief valve in the block's oil circuit so the element is not destroyed when the oil is cold and viscous. SAE paper 760110, page 8. Library →
It is a claimed feature of the engine: no groove in the cap-side half shells, offset by the routing of the oil passage in the crankshaft, which lubricates the rod journal continuously. Removing the groove reinforces the oil film at every moment when gas pressure exceeds the inertia forces of the piston/rod assembly — and it is that reinforcement which helps eliminate noise under load. SAE paper 760110, page 8. Library →
At 1.10 times crankshaft speed, belt-driven, with a stationary seal and a single outlet. Its pressure-output curves were measured at 85 °C (185 °F). The output is then split and feeds both banks through a double manifold bolted directly to the block. Regulation is by a three-way thermostat with an expanding wax sensor. SAE paper 760110, page 8. Library →
By calibrated holes in the two cylinder head gaskets — not by the circuit itself. The gasket meters the water cylinder by cylinder: one more reason not to fit just anything there. The water jacket is 5.8 mm thick at the upper flange and 9.5 mm along the liners, for a 108 mm liner centre distance. SAE paper 760110, page 8. Library →
The conventional distributor has two breakers and a double high-voltage rotor, to work with one coil per bank. The method is asymmetric: time it with a strobe on the left bank mark only, by rotating the distributor body; the right bank is then set by its own breaker, reachable from outside the distributor. Checking the dwell angle on the right-hand breaker then tells you whether the parts are correct and compatible. The distributor is driven by the right-hand camshaft, and its rigid mounting on the head keeps vibration particularly low. SAE paper 760110, page 9. Library →
8.65:1 in Europe and 8.2:1 in the USA — the gap comes from American emission requirements. Oil capacity 6 dm³, bore × stroke 88 × 73 mm, displacement 2664 cm³, cylinder bore spacing 108 mm. SAE paper 760110, page 14 (Appendix I). Library →
4.5 daN/cm² held by the pressure regulator, and a pressure drop across the metering slots kept constant at 0.1 daN/cm² by a diaphragm valve. Fuel is pressurised by an electric roller-type pump. On switching off, the supply is positively cut to prevent run-on. SAE paper 760110, page 16 (Appendix II). Library →
For five reasons the authors list: direct load sensing by the air metering device, which continuously measures air flow through the engine; simple injectors, since injection is continuous; fewer and simpler service requirements — most components can be checked with a fuel pressure gauge; partial altitude compensation by the metering device; and less influence of the EGR rate on actual air/fuel ratio, since actual air flow is measured. SAE paper 760110, page 11. Library →
Because air distribution between cylinders becomes critical as soon as air and fuel arrive separately: a cylinder-to-cylinder variation then translates directly into a variation in richness, not merely in charge. For markets with moderate requirements, a single manifold shaped like a six-legged crab straddles the metering unit placed low in the V. For the US injection version, a dual manifold with a dual-throat throttle: total flow is measured once, then split in two, each manifold feeding the opposite bank — which allows comparatively long intake ducts. SAE paper 760110, pages 11 and 12. Library →
Oxidation converters, whose active substance is a platinum/palladium mixture deposited on a monolithic ceramic substrate. They came with a whole emission-control kit: an anti-evaporation canister and fuel tank pressurising system (some models with a purge valve that prevents purging at idle); exhaust gas recirculation, either on-off or proportional, disabled at idle, when cold and at full load; and secondary air injection by a belt-driven vane pump, with a diverter valve and a check valve. SAE paper 760110, page 13. Library →
The seven-tooth gear pump, common to every PRV V6 since the 1990 model year — the brochure says so plainly. It markedly improves the engine's noise level. PRV Z7X-744 brochure, page 4. Library →
Specific gaskets, asbestos-free, with stainless steel fire rings. Specific means what it says: they are not the ones used on other PRV V6s. PRV Z7X-744 brochure, page 4. Library →
Because it is new, and its sealing was improved by a direct connection, with no hose and no clip. The new, more efficient water pump raises the main flow by 30% and the heater matrix flow by 100%: better engine cooling, markedly better cabin heating. PRV Z7X-744 brochure, page 4. Library →
Yes: an electric pump keeps the turbocharger cooling circuit running after the engine stops. The bay also gets two fans: one cools the injector rails and each injector, the other ventilates the turbo and the engine bay. PRV Z7X-744 brochure, page 4. Library →
Viton rotating seals, fitted in place of silicone ones: better resistance and better sealing. PRV Z7X-744 brochure, page 4. Library →
88 °C, on the Z6W-A700 as on the Z7U-730. Pressurised liquid cooling with an expansion tank, and two 290 mm, 120 W electric fans. élan no. 77, February 1985, page 4. Library →
Two Solex: a single-barrel 34 TBIA and a twin-barrel 35 CEEI. Fuel is supplied by an electric pump controlled by a tachometric relay, with a filter; air comes through a thermostatic flap air cleaner. The turbocharged Z7U-730, for its part, has two electric pumps, one of them submerged in the tank. élan no. 77, February 1985, page 4. Library →
Under pressure from the engine circuit, with an oil/water heat exchanger. The Garrett T3 turbocharger sits at the rear of the V, with an air-to-air intercooler and a compressor bypass valve. Engine lubrication stays conventional — filter and chain-driven gear pump, large-capacity light-alloy sump. élan no. 77, February 1985, page 4. Library →
Super, with an octane requirement of 97/99 — for both engines, the naturally aspirated Z6W-A700 and the turbocharged Z7U-730 alike, despite their very different compression ratios (9.5:1 against 8.6:1). élan no. 77, February 1985, page 4. Library →
The manual gives them as tooth counts, for the index 000 PK9 fitted to the B 545: 1st 11/43 · 2nd 19/42 · 3rd 31/43 · 4th 41/40 · 5th 41/31 · reverse 11/40 with a 29-tooth idler. Final drive 23/79, speedometer drive 5/14. Converted into ratios — calculated from the tooth counts, as the manual does not publish them: 3.909 · 2.211 · 1.387 · 0.976 · 0.756; reverse 3.636; final drive 3.435. Fourth is therefore already an overdrive, if only just. Safrane Bi-Turbo manual, folio 21-1. Library →
PK9 gearbox: 2.1 litres minimum, 2.6 litres maximum — plus 0.25 litre for the filter, because this gearbox has one. OT2 axle: 1.3 litre. Both take the same oil, ELF Tranself TRZ 75W-80W, to API GL5 or MIL L2105 C or D. Safrane Bi-Turbo manual, folio 04-7. Library →
10 litres of Glacéol AL (type C), and the manual is categorical about topping up: add demineralised water only. Protection down to −23 °C for hot, temperate and cold climates; down to −40 °C for very cold climates. Safrane Bi-Turbo manual, folio 04-7. Library →
Brakes: 1 litre for the ABS circuit, grade SAE J 1703 and DOT 3 — the manual adds that fluids must be approved by the design office. Power steering: separate 1.1 litre reservoir, ELF Renault matic D2 or Mobil ATF 220. Fuel tank: about 76 litres, unleaded. Safrane Bi-Turbo manual, folio 04-7. Library →
Because rubber, mostly latex-based, has a limited life. On the water side, the heat of the coolant “cooks” it: the hose turns porous, then cracks under engine vibration, seals less and less, and a small overheat can make it burst. On the air side, rubber is too soft: pressure and vacuum change its diameter, and on a turbo engine the intake hose collapses when the turbo comes on boost, cutting the flow. Automotive silicone takes −60 to 250 °C without degrading, is reinforced with several plies of fabric and resists tearing and deformation while staying just flexible enough. GTI Tech, pages 51 to 53. Read the article →
Not all of them. Silicone does not withstand hydrocarbons: for oil and fuel circuits, use hoses specifically made for that purpose. Silicone shines on the air and coolant circuits. GTI Tech, pages 52 and 55. Read the article →
Wide clamps with bevelled, non-cutting edges — the “trunnion” type — especially on the intake. A narrow clamp of the plain worm-drive kind concentrates its clamping force on a tiny part of the sleeve and its edges are often sharp: over-tightened, it cuts the hose, silicone or not. Since a clamp's force is spread over the whole circumference, there is no point in tightening hard; a 13 mm spanner drives that type of clamp, and a screwdriver lets you feel the torque better than a ratchet. Before fitting: degrease the sleeve (brake cleaner) so the hose does not creep, check that nothing is left inside a new hose, and slip the clamp on before the hose. GTI Tech, pages 54 and 55. Read the article →
Yes. When a reference is not in the catalogue, a specialist firm makes the part from the original hose — and can improve it: the pre-turbo hose fitted in the GTI Tech article, on a PRV V6 Turbo, was lengthened by a few centimetres so it no longer slips off when the engine rocks; a breather port can be deleted, or a boss added for a dump valve. Colours: red, blue or yellow, or black for a near-invisible change. GTI Tech, pages 52 to 54. Read the article →
Because the liner seats are narrow — a weak point of the engine — and corrosion, always worse on the timing side, can turn into a leak. The rule the Carbu column takes from PRV Concept: never do a head gasket on a PRV without pulling the liners. A seat can be built up by welding to fill every irregularity, but the column puts that at over 1,000 euros. Carbu, page 40. Read the column →
The Carbu column shows PRV Concept demonstrating Fenix Viewer, a piece of software written by an enthusiast known online as Max Fly, which replaces the Renault XR25 tester: bought online for about 150 euros at the time, delivered by email, with the cable following by post. Carbu, page 39. Read the column →
A 235 DT 8250. The manual's identification table fits on one line: vehicle type B 545, engine Z7X, displacement 2963 cm³, clutch 235 DT 8250, manual gearbox PK9. Safrane Bi-Turbo manual, folio 01-1. Library →
27 road models plus the Peugeot P4 V6 civilian series, across 11 marques: Peugeot (504, 505, 604, 605, P4 V6 civil), Renault (25, 30, Safrane, Laguna, Espace), Volvo (260, 760, 780, 960), Alpine (A310, GTA, GTA Le Mans, A610), Venturi (200, 260, 400 GT), Citroën XM, Talbot Tagora, Lancia Thema, DeLorean DMC-12, Dodge Monaco, and Eagle (Medallion, Premier). Every model has its own detailed file — see the Vehicles page.
The 960, and few people know it. When it replaced the 760 in 1990, most markets got Volvo's all-new aluminium 24-valve straight-six — not a PRV. Japan and Australia were the exception: their first 960s kept the B280 V6. Japanese type approval names the engine in the car's own code, E-9B280: V6 SOHC, 2,848 cc, 145 bhp, on sale from September 1990. Australia lists the 1991 960 GLE at 2,849 cc, 108 kW at 5,100 rpm, 235 Nm at 3,750.
No. The 740 is the four-cylinder sister of the 760: it shared the body and the platform, but never the V6. Its engines were the 2.0 and 2.3 petrol fours (B19, B200, B204, B23, B230, B234, naturally aspirated and turbo) and the D24 straight-six diesel. The PRV in the 700 series is the 760's — and the 780's.
The DeLorean DMC-12 — the 1985 Back to the Future time machine — is powered by the PRV V6: a 2.85-litre, 130 bhp unit (code ZMJ-159) mounted at the rear. In the first film its engine roar was dubbed with a Porsche 928 V8, but the real engine is the PRV. DeLorean file → The Journal article →
The Venturi 400 GT, nicknamed “the French F40”: its 2,975 cc 24-valve PRV, twin-turbocharged by EIA, delivers 408 bhp — the highest output ever reached by the Douvrin V6 in a road car. 400 GT file →
On 11 June 1988, the WM P88 — powered by a 910 bhp twin-turbo PRV — was clocked at 407 km/h on the Mulsanne straight, driven by Roger Dorchy. The chicanes added in 1990 mean this all-time Le Mans speed record still stands. Record file → The Journal article →
A catalogue Renault sold from 1994 to 1996: its 3.0-litre PRV (Z7X) was twin-turbocharged by German tuner Hartge to 268 bhp, with all-wheel drive, the body and assembly handled by Irmscher. Only 806 were built. Safrane Biturbo file →
The Renault 25 Limousine of French president François Mitterrand: stretched and armoured by Heuliez, powered by the 2.7-litre (144 bhp) or 2.5 turbo (182 bhp) PRV, built in 832 examples between 1986 and 1988. R25 file →
The Volvo 264, in October 1974, with the 125 bhp carburetted B27A. Volvo 260 file → · Volvo 760 file → · Volvo 780 file →
The Renault 30 (Z6V, 131 bhp): the flagship for which the PRV's development was accelerated. Renault 30 file →
The carburetted Volvo 264: 125 bhp (B27A) — at the other end of the scale from the Venturi 400 GT's 408 bhp.
Five models: 504 Coupé & Cabriolet, 604, 505, 605 — and the P4 V6, a very limited civilian series. 504 file → · 604 file → · 505 file → · 605 file → · P4 V6 file →
Yes — in a very limited civilian series of around fifteen examples, produced around 1991–1992 by FAM. These P4s were fitted with the ZN3J, the 2.8-litre fuel-injected PRV V6 of the Peugeot 505 (170 bhp). They are among the rarest PRV-powered vehicles in existence. Separately, Peugeot Talbot Sport used a bored-out version — the ZN3J3 (2,975 cc, ≈ 220 bhp) — as a rapid-assistance vehicle at the Dakar rally from 1987. P4 V6 file → · P4 Dakar section →
Five models: 30, 25, Safrane, Laguna (phase 1) and Espace. R30 file → · Safrane file → · Laguna file → · Espace file →
The 260 series (264, 265, 262C coupé), then the 760 and 780 — until 1997. Volvo 260 file → · Volvo 760 file → · Volvo 780 file →
Four rear mid-engined models: A310 V6, GTA, GTA Le Mans and A610. A310 file → · GTA file → · GTA Le Mans file → · A610 file →
The 200, 260 and 400 GT — the later 300 Atlantique switched to the L7X and falls outside the scope. Venturi 200 file → · Venturi 260 file → · 400 GT file →
The DeLorean DMC-12, the Eagle Premier, the Eagle Medallion and the Dodge Monaco. DeLorean file → · Premier file → · Medallion file → · Monaco file →
Seven models: Peugeot 504 and 604 (2.7-litre, 136 bhp), Renault 30 (131 bhp), Volvo 260 (125 bhp), Alpine A310 V6 (150 bhp), Talbot Tagora (166 bhp — the most powerful carburetted 2.7) and, the only 2.8, the naturally-aspirated Alpine GTA (160 bhp). All vehicles →
K-Jetronic injection equips six models: Peugeot 604 (144 then 155 bhp), Renault 30 TX and Renault 25 (144 bhp), Volvo 260 then 760 (140 to 155 bhp) and the DeLorean DMC-12 (130 bhp). PRV engines →
The norm from the 1980s onwards — some twenty models: Peugeot 505 V6, 605 and civilian P4, Renault 25 (atmo and Turbo), Safrane, Laguna, Espace, Volvo 760 and 780, Alpine GTA Turbo, GTA Le Mans and A610, the three Venturis, Citroën XM, Lancia Thema 6V, Dodge Monaco, Eagle Medallion and Premier. All vehicles →
Six production models: Renault 25 V6 Turbo (2.5-litre, 182 then 205 bhp), Alpine GTA V6 Turbo (200 bhp) and GTA Le Mans (185 to 210 bhp), Venturi 200 (200 bhp), Venturi 260 (2.8-litre, 260 bhp) and Alpine A610 (3.0-litre, 250 bhp). The first was the Renault 25 in 1985, with the Z7U. Z7U file →
Only two production cars, both in 1994: the Renault Safrane Biturbo (268 bhp, developed by Hartge) and the Venturi 400 GT (408 bhp, 24 valves). Before them, Legend Industries' DeLorean Twin Turbo (four cars converted, two of them twin-turbo) did not survive DMC's bankruptcy; around 1995 Hartge built a single 280 bhp Laguna Biturbo prototype. In racing and concept cars: the record-breaking WMs (up to 910 bhp), the Peugeot Oxia (680 bhp) and the Venturi 600 LM (~600 bhp). Safrane Biturbo file → · 400 GT file →
Almost all of them: the production PRV is a 12-valve (one camshaft per bank) from 1974 to the end of its career — Safrane Biturbo included. Only three road cars are exceptions, with a 24-valve head: Peugeot 605 SV24, Citroën XM V6 24S and Venturi 400 GT. ZPJ4 file →
Three road cars: Peugeot 605 SV24 and Citroën XM V6 24S (ZPJ4 with the ACAV variable intake, 200 bhp, from 1990), and the Venturi 400 GT (24-valve twin-turbo, 408 bhp, 1994). Among concept cars and racers: the Peugeot Oxia (680 bhp) and the Venturi 600 LM (~600 bhp). ZPJ4 file →
Yes: the Espace V6 carried the 153 bhp catalysed Z7W 707 — the same engine as the catalysed Renault 25. Espace file →
The Z7X 744: the 250 bhp turbocharged 3.0-litre PRV — the culmination of the PRV Alpine line. A610 file →
The naturally-aspirated 160 bhp Z6W-A, the 200 bhp Z7U 730 turbo, and the 185 bhp catalysed Z7U 734 on the GTA Le Mans (210 bhp with the Danielson preparation). GTA file → · GTA Le Mans file → · A310 file →
The 167-170 bhp 12-valve ZPJ, then the 200 bhp 24-valve ZPJ4 on the XM V6 24S — shared with the Peugeot 605. XM file → · 605 file →
The 12-valve ZPJ (167-170 bhp), and the 200 bhp 24-valve ACAV ZPJ4 on the 605 SV24. 605 file → · XM file →
Three PRVs depending on the version: 136 bhp ZM·ZMS (SL, carburettor), 144 bhp ZMJ (Ti and STI, K-Jetronic), 155 bhp ZNJ (GTI, 2,849 cc). ZM file → · ZMJ file → · ZNJ file →
The 2,849 cc LH-Jetronic ZN3J, 170 bhp — the same code as the Lancia Thema 6V's.
Yes: a 166 bhp carburetted 2,664 cc — the most powerful 2.7-litre version in a road car. Tagora file → · Thema file →
Yes, the Thema 6V: the 147-150 bhp ZN3J — the only Italian among the eleven PRV marques. Thema file → · Tagora file →
The Safrane Biturbo (1994-1996): Z7X 726 by Hartge, 268 bhp, 806 built. Safrane Biturbo file →
Its gearbox. The PK9 — derived from the V6 Quadra's PK7, with strengthened gears — remained a naturally aspirated saloon's transmission and could not take the torque of two turbochargers: power was capped to preserve it. With a gearbox to match, Hartge could have gone beyond 300 bhp. The architecture did not help: on a front-wheel-drive car with a transverse engine, adding four driven wheels forces the torque through a right angle inside an already crowded volume. The Journal article →
Yes: a 144 bhp 2.7-litre (Z7V) then a 160 bhp 2.8-litre (Z7W 706, 153 bhp catalysed), before the 182 and 205 bhp V6 Turbos. R25 file →
The 156 bhp LH-Jetronic B280 — the same as the 760. The elegant coupé of the Swedish range. Volvo 780 file → · Volvo 760 file →
The coupé of the 260 series: 126 bhp SU-HIF6 carburetted B28A, or 140 bhp B27F for the US market.
A table in the brochure lines them up, code and displacement: Alpine A310 — 112-7, 2664 cm³; Alpine V6 GT — Z6W A700, 2849 cm³; Alpine V6 GT turbo — Z7U 730, 2458 cm³; Alpine V6 turbo A610 — Z7X 744, 2975 cm³. The 1985 turbo is therefore the smallest of the four in displacement: forced induction, not capacity, made the difference — until the A610 took both. PRV Z7X-744 brochure, page 4. Library →
The brochure's chart gives the four milestones, in EEC hp and torque: A310 150 hp (110 kW), 20.8 m-kg (204 Nm) — V6 GT 160 hp (118 kW), 23 m-kg (225 Nm) — V6 GT turbo 200 hp (147 kW), 28.6 m-kg (280 Nm) — A610 250 hp (184 kW), 35.7 m-kg (350 Nm). Average recorded consumption (town / 120 kph / 90 kph) dips then rises: 10.2, then 9.66, then 9.16 l/100 km, and 10.4 for the A610 — which therefore drinks barely more than the A310 while giving a hundred horsepower more. PRV Z7X-744 brochure, page 4. Library →
Top speed, 0-100 kph, standing 400 m and 1000 m: A310 225 kph, 7.8 s, 15 s, 27.8 s — V6 GT 235 kph, 8 s, 15.5 s, 28 s — V6 Turbo 250 kph, 7 s, 14.5 s, 26.8 s — A610 265 kph, 5.9 s, 14.1 s, 25.7 s. PRV Z7X-744 brochure, page 4. Library →
Displacement first: 3 litres against 2.5. Then, in the detail the brochure gives: improved cylinder head permeability — their ability to pass gas flow in and out of the chamber —, a straightened-duct intake manifold, a Garrett T3 with reduced response time to hold performance at every engine speed without touching the valve gear, which stays conventional, and a new camshaft profile. PRV Z7X-744 brochure, pages 2 and 3. Library →
7% more power and 11% more peak torque. élan 77 gives the five reasons: displacement raised to 2.849 l, the bore going from 88 to 91 mm; more camshaft overlap; a new ignition curve; an exhaust worked for low-end torque; and fresh air drawn in at the rear spoiler, in a high-pressure zone — what the magazine calls “natural supercharging of the engine”. élan no. 77, February 1985, page 4. Library →
200 hp instead of 182, although it is directly derived from it. élan 77 lists: more direct air ducts and an intercooler with lower pressure losses; an exhaust with lower back pressure; a specific dynamic boost control; and specific ignition and injection settings, the Renault Alpine being both lighter and more aerodynamic than the Renault 25 V6 Turbo. élan no. 77, February 1985, page 4. Library →
An “exceptional” drag coefficient of 0.28 to 0.30. The car is built on a stressed polyester body over a steel backbone chassis — hence its contained weight. Its 80-litre tank gives it a range of over 800 km. élan no. 77, February 1985, page 3. Library →
Cheap to buy, demanding to keep, as the association told the magazine Carbu. Check that the intake duct is airtight: a damaged duct makes the turbo overspeed to make up the pressure loss, and wears it out. Run a good engine oil (Motul 15W-50 is the example given), possibly with a film-strengthening additive. And above all go through the cooling system thoroughly before using the car: PRV Concept recommends a “greasy” coolant — the members mentioned Glysantin for aluminium, without having tested it; the prepared engine in the article runs on Glaseol, found at Renault or AD — and says to avoid at all costs the red Type C coolant of the phase 2 cars. The association also notes more liner-seat trouble on the 205 hp. Carbu, page 38. Read the column →
The Carbu column's timeline. 1984: the R25 range is launched, topped by the V6 Injection with the 2,664 cm³ PRV (88 × 73 mm), 144 hp, K-Jetronic. 1985: the R25 V6 Turbo arrives with the 2,458 cm³ Z7U (91 × 63 mm), 182 hp, Renix injection; in July the V6 Turbo Limousine built by Heuliez, produced until the end of 1987. 1988: the 25 V6 gets the 2,849 cm³ (91 × 73 mm) with split crankpins and Bendix injection, the automatic keeping the 2,664 cm³; the range is restyled in May. March 1990: the de-polluted V6 Turbo, 205 hp. February 1992: end of R25 production. Carbu, page 38. Read the column →
According to the Carbu column, the 205 hp is the most accomplished 2.5 Turbo: a less domed piston, hence a lower compression ratio, with boost pressure up by 200 g; a boost-pressure regulating valve; reinforced main bearings — the two transverse bolts per bearing first seen on the Alpine blocks; a Fenix 3B control unit with an EPROM, where the phase 1 box had no chip; a turbo with a larger compressor wheel, water-cooled with an electric pump that runs after shutdown, whereas the 182 hp cooled its turbo with a simple air blower for 12 minutes after switch-off (later triggered by a thermal sensor); a continuous throttle-position system instead of the 182's micro-switch; fuel pressure of 3 bar on the 182 hp and 2.5 bar on the 205 hp. The 205 hp was developed by BEREX at Alpine in Dieppe, and its type plate inside the V, next to the water pump, reads 700 where the 182 hp reads 702. Carbu, pages 40 and 41. Read the column →
élan 77 gives four readings, GT then Turbo: at 90 kph 7.00 and 6.4 l/100 km; at 120 kph 7.90 and 8.1; on the urban cycle 14.70 and 12.8; UTAC average 9.86 and 9.10 l/100 km — against 10.9 for the A310, “which was reputed frugal given the performance achieved”. A gain of 10 to 17%. ⚠️ Do not confuse these with the 1991 brochure, which publishes slightly different averages for the same cars (9.66 and 9.16, and 10.2 for the A310): the measurement basis differs. élan no. 77, February 1985, page 3; compare with the PRV Z7X-744 brochure, page 4. Library →
The WM team's goal: to break 400 km/h on the Mulsanne straight at Le Mans. Achieved on 11 June 1988 with the P88: 407 km/h. Record file →
The driver of the WM P88, clocked at 407 km/h on the Mulsanne straight on 11 June 1988 — the highest speed ever recorded at Le Mans.
Two Peugeot designers, founders of the WM team, entered at Le Mans every year from 1976 to 1989 — always on PRV power.
To coincide with the launch of the new Peugeot 405. The speed actually measured was 407 km/h.
Two chicanes were added to the Mulsanne straight in 1990, capping speeds well below 400 km/h: the record became eternal.
Around 910 bhp: its 2,974 cc ZNS5 with 24 valves and two turbochargers — the most powerful PRV ever built.
The 1988 Paris Motor Show concept: a WM-tuned 24-valve twin-turbo PRV, 680 bhp at 8,200 rpm, 726 Nm, 350 km/h in testing — four-wheel drive and steering. Oxia file →
The competition version of the Atlantique, entered in the BPR series and at Le Mans in the mid-1990s: an EIA-developed 24-valve bi-turbo PRV of around 600 bhp. 600 LM file →
The P82 (600 to 890 bhp depending on boost, 2.7-litre Garrett twin-turbo) and the P87 (890 bhp, 2.8-litre), the first attempt at the 400 Project — just short.
The German tuner Renault entrusted the Safrane's V6 to: two turbos, 268 bhp (Z7X 726). It also built a 280 bhp Laguna Biturbo prototype around 1995. Safrane Biturbo file →
A Hartge prototype from around 1995: the 3.0-litre bi-turbo PRV lifted to 280 bhp in a far lighter front-wheel-drive car. Burned by the Safrane Biturbo's flop, Renault refused production — around five to seven were built.
The dealer-homologated kit that took the Alpine GTA Le Mans from 185 to 210 bhp — one of the few officially sold PRV preparations. All tuners →
Anything but a chip: a deep engine overhaul entrusted to the BEREX design office — compression ratio lowered from 8.6 to 8.0:1, strengthened block and bearings, oil pump, camshafts, turbo and Fenix 3B management reworked, catalytic converter. That is what took the Renault 25 V6 Turbo from 182 to 205 bhp in 1990. The Journal article →
A young French outfit's late-1980s conversion, sold as “Storming” and nicknamed “the R25's AMG”: 240 bhp DIN at 5,700 rpm from the 182 bhp V6 Turbo (an extra intercooler, turbo, electronics and suspension reworked), around ten built. R25 file → The Journal article (M6 report) → The HAS brochure →
HAS's price list of 15 October 1988 sells the 240 bhp “Storming” engine conversion at 41,500 francs including VAT, the suspension, declared indispensable, at 8,800 francs, and the body kit at 13,700 francs fitted and painted for a phase 2 car, 12,700 francs for a phase 1. An order form dated 16 May 1989 comes to 84,781.50 francs including VAT for the engine, suspension, wheels, tyres, exhaust and body kit. The HAS brochure (Library) →
Venturi's engine house: it turbocharged the PRVs up to 260 bhp (260), 408 bhp (400 GT) and around 600 bhp (the racing 600 LM). 400 GT file →
Hartge's German partner on the Safrane Biturbo: widened body, bespoke interior and final assembly of the 806 cars.
A twin-turbo DMC-12 project whose output was never published (around 200 bhp by repute); four cars were converted, two of them twin-turbo, before DMC's 1982 bankruptcy killed it. Four conversions does not mean four engines: Legend also sold engines outside them — the owner of DeLorean no. 1860 recounts buying his directly from the firm. DeLorean file → The Journal article →
Three engines were studied before it: the Comotor twin-rotor Wankel of the Citroën GS Birotor, dropped with Citroën's bankruptcy in 1974; Ford's “Cologne” V6 from the Capri and Granada, long the favourite; and the Citroën CX's 2-litre four, found too weak. The PRV cost more than the Cologne, but it was lighter and more powerful, Renault had capacity to spare at Douvrin — and above all the engine was already certified in the United States: displacement aside, it was the Volvo 260's, and the US Environmental Protection Agency let DMC skip the 50,000-mile durability test. With it came the Renault 30 gearboxes, which put the V6 lengthways behind the rear axle. The Journal article →
The engine is not to blame: it is a matter of fuel pressure. K-Jetronic injection must stay pressurised once the ignition is off — 3.3 bar of rest pressure at switch-off, and still at least 1.7 bar after 10 minutes. If it collapses, the heat of the stopped engine boils the fuel in the injector lines lying in the vee, and there is nothing but vapour behind injectors that only open at 3.5 bar: you crank until the vapour is purged. The usual culprits: the fuel accumulator, the pump's check valve, a seal in the fuel distributor, a mixture set too lean — sealed parts that are replaced, not repaired. The 144 bhp Renault 25 V6 injection (Z7V) asks for the same values. DeLorean workshop manual, folio D:02:01. The Journal article →
17 million dollars “for engines”, according to a UPI dispatch from London dated 22 October 1982: Renault was DMC's biggest creditor. On 16 November 1982 a bankruptcy judge approved the sale of the assets for 1.5 million dollars; Renault and the British government were among the secured creditors — 17 million each — and the settlement came to about 3 cents on the dollar. Between late 1980 and 24 December 1982, about 9,000 DeLoreans left Dunmurry (8,975 by the most quoted count), and so at least as many PRV V6s left Douvrin. The Journal article →
A leading figure at the Centre Alpine in Boulogne: from 1987 he built what is regarded as the most accomplished GTA V6 Turbo — 2.8-litre and Garrett T3 turbo, around 250 to 265 bhp depending on sources. All tuners →
Not as a competition car, but as a rapid-assistance vehicle. From 1987, Peugeot Talbot Sport (PTS) fitted Peugeot P4 4×4s with a bored-out PRV — the ZN3J3 (2,975 cc, lightened flywheel, reworked camshafts, specific mapping, ≈ 220 bhp) — to support the 205 T16 and 405 Turbo 16 entries. Citroën Sport continued the practice into the 1990s for its own Dakar campaigns. Around twenty units were built in total. P4 Dakar section →
A phase 1 Renault Safrane V6 RXE — crossed in 1993 by a medieval knight in one of the biggest hits in French cinema history. Pop culture →
A phase 1 Renault 25 V6 injection (Z7V, 144 bhp), in Jan Kounen's hyper-stylised 1997 crime film with Vincent Cassel and Monica Bellucci.
No: in the first Back to the Future, its sound was dubbed with a Porsche 928 V8. The real engine is the 130 bhp PRV V6. DeLorean file →
The Volvo 264 TE: stretched 70 cm and bodied by Bertone, the official car of East German leadership. Two open-topped Landaulet versions were built for parades.
One Landaulet survives at the GDR Museum in Berlin, the other in a museum in South Korea.
The nickname of François Mitterrand's presidential motorcade: the Heuliez-stretched, armoured Renault 25 Limousines — 832 built between 1986 and 1988. R25 file →
PRV Concept is a French enthusiasts' association, active since 2009, dedicated to preserving the PRV V6 heritage. It runs this reference site, a community forum and a shop at prv-concept.com, plus a Facebook group.
In the site's Library section (bibliotheque.html): period workshop documents readable page by page in the built-in viewer, starting with the Renault repair manual for the Z engine family.
On the PRV Concept forum (prv-concept.com/forum), where the community shares mechanical advice, documentation and finds — or in the association's Facebook group.
970,315 engines between October 1974 (first unit fitted in a Volvo 264) and 15 June 1998, when the last PRV V6 left the Douvrin production lines.
W782000389 — PRV Concept is a registered association under the French 1901 law. About page →
Two members: Cédric Barme (“machouse”), president and treasurer, and Anaïs Barme (“maya”), secretary. About page →
“Their union is our strength” — the union of Peugeot, Renault and Volvo yesterday, that of the community today.
By email at president@prv-concept.com, on the forum, or via the association's Facebook group.
Yes: a full English version is available under /en/, with the same engine, vehicle and prototype files.
When writing a post, tap “Add photos” under the text box: your camera roll opens, you can pick several photos at once. They appear as thumbnails before being sent; one tap on a thumbnail inserts it into the post, “Insert all” puts them all one per line, and “Submit” publishes. iPhone HEIC and Android WebP are accepted, photos are downsized before sending, metadata (including GPS) is removed and orientation is kept. Up to 20 photos per post, 12 MB each. The article, with a video demo →
No. The forum account opens the shop: signed in on the forum, you arrive on the shop already recognised, without a second password. Registration happens on the forum. Details in the Journal article “The site, the forum and the shop are now one”.
If its email address is the one of your forum account, sign in once on the shop with its password: the two accounts are then linked, and the forum is enough afterwards. Forgotten password? The shop's “My account” page sends a new one.
No. They now share the site's header, menu and footer, but their addresses, topics, posts and orders are the same.
Period workshop documents readable in the built-in viewer, starting with the Renault repair manual for the Z engines (Z6V, Z7U, Z7V, Z7W, Z7X). Library →
Yes. GTI Tech devoted an article to the silicone hoses of the PRV V6, produced with the association, and the magazine Carbu ran a “PRV Concept” technical column on the PRV V6 and the Renault 25 V6 Turbo. Both articles can be read in the Library, PRV Concept section.
From cross-checked public sources — Wikipédia, CarJager, Caradisiac, News d'Anciennes, Forum-Auto, Culture Auto — and period manuals; every sensitive fact carries a reliability badge. Sources & methodology →
Yes. Père Hervé — the piston-headed workshop foreman in the bubble at the bottom of every page, in the shop and on the forum — is an artificial intelligence set up by the association. He only reads the Library, the forum topics and the shop; without a source he does not answer, and every message he prepares for the forum is read by a human before publication. He can be wrong: the manual is the authority, not him. The article about him →
A question missing? Ask it on the forum — the best answers end up here and across the site.
Every answer above is developed in the site's sections — history, engines, cars, tuners, racing and pop culture.
