Help please.....stalling problem
Discussion
I've been the proud owner of a 1998 Rosso pearl Griff for the past 18 months, during which time it hasn't missed a beat.....until now. The car only gets run at weekends and the Sunday before last we'd gone for the usual blast along local country lanes. Everything was perfectly normal until about half a mile from home when, stuck in dawdling traffic, the car suddenly started kangarooing on part throttle. Having limped home it sat idling in the drive no problem. I switched off and let it cool down for 10 minutes and then restarted and went for a quick run around the block. No problem at all - part throttle, full throttle, idling all back to normal. I put the car in the garage and hoped it was a one-off....
However, came to start it this Sunday and it fires no problem, idles evenly at 1K rpm, then after about 30 seconds just cuts out. No coughing or spluttering, just as if I'd switched the ignition off. It re-starts no problem and then does exactly the same thing again. After that it wouldn't start again for several hours (there was a strong smell of petrol so I,m guessing it was flooded). So I tried again later and it starts and idles as normal and then cuts out again after 20 seconds. Also, if you try to blip the throttle to stop it stalling it instantly cuts out. I did manage to catch it once, and tried to keep the revs up at 2 to 2500 rpm. It sounded to be mis-firing and the instant I let the revs drop below 2000 it stalled immediately.
I've searched all previous posts with similar problems but can't find anything with exactly the same symptoms. I've cleaned the stepper motor, and tried disconnecting the vaccuum advance pipe but neither has made any difference. The previous owner had a Mark Adams Tornado chip fitted and, up until now, its always idled smoothly, never stalled, never mis-fired and had pin-sharp throttle response....which makes this all the more annoying!
Any advice will be gratefully received!!!
However, came to start it this Sunday and it fires no problem, idles evenly at 1K rpm, then after about 30 seconds just cuts out. No coughing or spluttering, just as if I'd switched the ignition off. It re-starts no problem and then does exactly the same thing again. After that it wouldn't start again for several hours (there was a strong smell of petrol so I,m guessing it was flooded). So I tried again later and it starts and idles as normal and then cuts out again after 20 seconds. Also, if you try to blip the throttle to stop it stalling it instantly cuts out. I did manage to catch it once, and tried to keep the revs up at 2 to 2500 rpm. It sounded to be mis-firing and the instant I let the revs drop below 2000 it stalled immediately.
I've searched all previous posts with similar problems but can't find anything with exactly the same symptoms. I've cleaned the stepper motor, and tried disconnecting the vaccuum advance pipe but neither has made any difference. The previous owner had a Mark Adams Tornado chip fitted and, up until now, its always idled smoothly, never stalled, never mis-fired and had pin-sharp throttle response....which makes this all the more annoying!
Any advice will be gratefully received!!!
Those problems partly match a knackered fuel pump relay: intermittant problem, oftens clears after it has had time to cool down, engine will *almost* run but dies if you so much as look at the throttle.
What doesn't fit is the strong smell of petrol and 2000 rpm misfire. That suggests either overfuelling, or an ignition fault. Ignition amplifiers and coils can both fail when hot and improve when cooled down.
To start with, I suggest you learn to recognise the sound of the fuel pump priming when you switch the ignition on. It should run for a second or so, and then stop. If you don't hear this then you've got a fuel system fault, almost certainbly an electrical fault in the supply to the pump, probably a faulty fuel pump relay.
Get yourself a cheap passive strobe light. I've got a set of small lights designed to clip into the HT leads, but I've also got a really cheap and nasty unamplified timing light that works even better. This will show whether you have a spark when it won't start. If you have no spark, then you're into electrical fault finding to track down the cause.
If neither of these simple tests show a fundamental fault with the fuel/ignition systems then you need to investigate whether the injectors are firing and whether the fuel pressure is correct. At this point you are going to need specialist test equipment and might want to call in the professionals - if you haven't already.
What doesn't fit is the strong smell of petrol and 2000 rpm misfire. That suggests either overfuelling, or an ignition fault. Ignition amplifiers and coils can both fail when hot and improve when cooled down.
To start with, I suggest you learn to recognise the sound of the fuel pump priming when you switch the ignition on. It should run for a second or so, and then stop. If you don't hear this then you've got a fuel system fault, almost certainbly an electrical fault in the supply to the pump, probably a faulty fuel pump relay.
Get yourself a cheap passive strobe light. I've got a set of small lights designed to clip into the HT leads, but I've also got a really cheap and nasty unamplified timing light that works even better. This will show whether you have a spark when it won't start. If you have no spark, then you're into electrical fault finding to track down the cause.
If neither of these simple tests show a fundamental fault with the fuel/ignition systems then you need to investigate whether the injectors are firing and whether the fuel pressure is correct. At this point you are going to need specialist test equipment and might want to call in the professionals - if you haven't already.
GreenV8S said:
Those problems partly match a knackered fuel pump relay: intermittant problem, oftens clears after it has had time to cool down, engine will *almost* run but dies if you so much as look at the throttle.
I had very similar symptoms and it turned out to be a loose spade connector to the fuel pump. Cost next to nothing to fix. Turns out several people have had the same problem - there was a thread on here only last week or the week before IIRCThanks for the suggestions. Over-fueling might be a possibility. The fuel pump definitely primes every time you turn on the ignition and the car starts and idles as normal for a while before cutting out of its own accord or if you even think of touching the throttle. I doubt that its temperature related as it first happened when hot and is now a starting from cold problem (I can't get it to run long enough to warm it up!). Incidently, when starting from cold the exhausts have always spattered the garage floor with black deposits (not oil) which would suggest that its running rich - or do they all do this?
I've heard in the past poor running blamed on a contaminated tank of fuel. I had filled it with Optimax from my usual station just 15 minutes before the problem started but surely this can't be more than a coincidence?
I've heard in the past poor running blamed on a contaminated tank of fuel. I had filled it with Optimax from my usual station just 15 minutes before the problem started but surely this can't be more than a coincidence?
I agree with what's been said so far.
Had the same symptoms (twice)on my V8S and the first time it proved to be the distributor. I assume that the internal electronics (?) broke down - giving almost identical symptoms as described. I went down the road of changing amplifier, coil etc and when cold it ran for up to 20 minutes then cut out, with a noticeable smell of petrol from the exhaust. In the end had to get a replacement dissy.
When the coil failed, I had been out in the car in the morning, went to take my daughter into town in the evening, and although the engine was trying to fire it would not run. Swapped the coil (left from the trials above) and bingo! Houston we have ignition!
I would definitely suspect 'sparks' if you can smell petrol out of the pipes.
Good luck Nick.
Had the same symptoms (twice)on my V8S and the first time it proved to be the distributor. I assume that the internal electronics (?) broke down - giving almost identical symptoms as described. I went down the road of changing amplifier, coil etc and when cold it ran for up to 20 minutes then cut out, with a noticeable smell of petrol from the exhaust. In the end had to get a replacement dissy.
When the coil failed, I had been out in the car in the morning, went to take my daughter into town in the evening, and although the engine was trying to fire it would not run. Swapped the coil (left from the trials above) and bingo! Houston we have ignition!
I would definitely suspect 'sparks' if you can smell petrol out of the pipes.
Good luck Nick.
[quote=maffman] Incidently, when starting from cold the exhausts have always spattered the garage floor with black deposits (not oil) which would suggest that its running rich - or do they all do this?
quote]
Mine's been Adams'd and does this. I don't think it's a problem on its own - but of course if you've got a spark problem then running rich at start up will wet the plugs even more quickly.
Incidentally I have had fuel pump problems stemming from a loose connector tag on the pump and the pump fuse arcing. I would get similar symptoms to you - including the smell of fuel. I assumed it's because the engine gets flooded once it stalls followed by the pump coming back to life, but the engine not firing immediately?...
quote]
Mine's been Adams'd and does this. I don't think it's a problem on its own - but of course if you've got a spark problem then running rich at start up will wet the plugs even more quickly.
Incidentally I have had fuel pump problems stemming from a loose connector tag on the pump and the pump fuse arcing. I would get similar symptoms to you - including the smell of fuel. I assumed it's because the engine gets flooded once it stalls followed by the pump coming back to life, but the engine not firing immediately?...
Thanks Guys, I think the consensus seems to be pointing towards electrics. Just my luck - I'm not too bad with the oily bits but car electrics have always been a mystery...
I think the first thing is to check some of the connections that have been mentioned - the fact that it happened so suddenly without any previous symptoms makes me think loose spade tag or similar. Then I think the next stage might be an auto-electrician. Even if they're not used to TVRs they should be able to spot faulty components and at least point me in the right direction.
I think the first thing is to check some of the connections that have been mentioned - the fact that it happened so suddenly without any previous symptoms makes me think loose spade tag or similar. Then I think the next stage might be an auto-electrician. Even if they're not used to TVRs they should be able to spot faulty components and at least point me in the right direction.
I intended to get to the bottom of this at the weekend but didn't have time to do anything other than check various connections and clean the stepper again...to no avail. The throttle pot does sound like a likely candidate. I came across several threads on the "S" forum with similar sounding symptoms - part throttle misfire/kangarooing, cold starting problems etc. The test on the Ford engine is to simply disconnect the throttle pot and if the engine starts and runs ok, thats the culprit. Does anyone know if it is as simple as that on the V8 engines?
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