Classic engine cut out

New Member, first post ,I recently began recommissioning work on my 1988 range rover TACR2 3.5 EFI petrol manual.
The issue i have, is after about a couple of minutes, when engine warms up it cuts out,
Any suggestions as to cause ?
Works undertaken to date without cure.
Tank drained flushed & new fuel added.
New fuel lines.
new spark plugs
Compression Test.
New temperature sensor
New fuel sensor
New coil

Styx said:

New Member, first post ,I recently began recommissioning work on my 1988 range rover TACR2 3.5 EFI petrol manual.
The issue i have, is after about a couple of minutes, when engine warms up it cuts out,
Any suggestions as to cause ?
Works undertaken to date without cure.
Tank drained flushed & new fuel added.
New fuel lines.
new spark plugs
Compression Test.
New temperature sensor
New fuel sensor
New coil

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I do not know that engine but the crank position sensor is often the culprit on other engines.

temp switch for ecu not gauge ,it allows over fueling for cold start like a choke ,but like a coke engine will stall when hot

Ignition amp.

'Oh drool, drool.
I've always liked the TACR2 (esp. the A) There's a yellow ex. Birmingham airport one on the market at the moment, fully restored for 7K.
Really tempted, but sadly nowhere to store it.
Really hope you can solve the problem.

nb. no CPS on a 3.5 RV8

jamesmartin said:

temp switch for ecu not gauge ,it allows over fueling for cold start like a choke ,but like a coke engine will stall when hot

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Saint.V8 said:

Ignition amp.

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Thanks for the advise, I have fitted a new amp module on the distributor but unfortunately without a cure, any other suggestions please ?
Regards Styx

Styx said:

Thanks for the advise, I have fitted a new amp module on the distributor but unfortunately without a cure, any other suggestions please ?
Regards Styx

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have you tried the first suggestion

jamesmartin said:

temp switch for ecu not gauge ,it allows over fueling for cold start like a choke ,but like a coke engine will stall when hot

Click to expand...

Hi James, thanks, temp sensor was one of the first things I changed out.

After cutting out have you checked for & do you have a good spark at the plugs?
Is this a flapper AFM & 4CU ecu or hotwire? (I would expect the former, but never a good idea to assume things!)

Would check the wiring at the coil and the spark modular... they are old and can break
In the plastic coating... so check anywhere you have moved them about...,
Also you might open the hood and observe
The motor running in the dark..,
It can reveal any arcing and is just fun to watch... can be quite the light show

Ratae said:

After cutting out have you checked for & do you have a good spark at the plugs?
Is this a flapper AFM & 4CU ecu or hotwire? (I would expect the former, but never a good idea to assume things!)

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spark is still good after cut out and its afm & ecu

Styx said:

spark is still good after cut out

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Which suggests the issue is fuelling not ignition.
Your system should have a 9th injector on the right hand side of the plenum. Disconnect its electrical connector. If this improves matters then you have a faulty thermotime sensor - which is the one in front of the ECU temp sensor. TBH it's not really needed anyway in this country & my 9th injector has been disconnected since I bought it in 1994.

How long before it will restart & is there any indication of overfuelling - black smoke on restart?
With the ignition on to the usual running position - but not running - if you gently push the flap in the AFM open can you hear the fuel pump running after the cutout? (You might need to have someone listening at the filler cap or you can prop the flap open & go & listen yourself)

Just to be absolutely sure is this the temp sensor you changed? ETC8496 https://www.johncraddockltd.co.uk/etc8496-g-lucas-temperature-sensor-v8-e-f-i-to-1998.html

Clean the crankcase breather flame trap and the hose to the plenum chamber, which if blocked can suffocate and stall the engine. If the issue was the EFI temp sensor the engine would misfire before finally stoping.
I had to clean my 3.5s breather a couple to stop the engine stalling in the 10+ of ownership, still do with my 3.9 just in case

discool said:

Clean the crankcase breather flame trap and the hose to the plenum chamber, which if blocked can suffocate and stall the engine. If the issue was the EFI temp sensor the engine would misfire before finally stoping.
I had to clean my 3.5s breather a couple to stop the engine stalling in the 10+ of ownership, still do with my 3.9 just in case

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The plenum passageway on mine was totally blocked when I bought it.
Didn't realise until it's first long distance run.
The crankcase had pressurised & oil was leaking from all over the place, seals & gaskets.
Finished the trip with the end of the hose into an improvised catch can which stopped the leaking.
Didn't affect the running at all.
I now treat flushing the flame trap & the internal plenum passageway as an annual service item.
Definitely worth doing.

The metal stub on the plenum that the hose goes onto is an interference fit & with care can be pulled out. This gives access to the length of the passageway. Prop the throttle butterfly open & look in. You'll see a smallish hole on the left as you look in. Push a clean lintfree cloth into the mouth of the plenum into the area of the hole & give a good blast of carb cleaner down the passageway from the pipe end. The cloth will soak up the crap.
Refit the metal stub correctly oriented with a smear of sealant.
While you're at it clean the area the butterfly closes onto & check the clearance between the lowest point of the butterfly & the plenum. The flapper 3.5EFi requires a gap of 0.05mm (0.002") clearance set using the stop adjustment screw against the stop lever.
If the passageways are clear & the hose is pulled off mine will stall.