Cutting out at idle - what might be causing it
Discussion
Hi all.
I thought I'd cured this issue by replacing the HT setup but it turns out I haven't.
I've so far replaced
Dizzy cap
HT leads
Ignition Amp
Spark plugs
Fuel
The Griff is in the wrong garage so I went to move it last night to its cozy home for the winter but it clearly has other ideas.
Here is what happened last night
Disconnect Accumate
Unlock car
Turn key so I can hear fuel pump (Its a habit)
Start
Lovely V8 rumble
Runs for about 30 seconds to a minute then dies. No cough, not running rough, just idling then dead, and it won't restart although I can hear the pump priming.
This morning I followed the same procedure and it won't start.
It turns over and over and over but makes no attempt to start.
The last time it did this I left it for a couple of weeks and it started first time. And about 5 times more, so I took it for a pootle down the road and back - maybe 2 miles or so - and popped it into Mrs B's garage as she was away.
Because of the way it dies and won't restart I'm beginning to think it might be the alarm killing the system, so I need to bin the alarm and get a new one, but have no idea how to test this.
I replaced the alarm a few years ago with one which was a straight plug-in replacement, which I detailed in the Griffith Parts List so I now know it was replaced Nov 2014
http://abacuscaralarms.co.uk/alarmshop/index.php?a...
I'll disconnect the battery tonight and leave it a few days then try again but I wondered if there was another way of testing for a dead system which might tell me the alarm is shutting something off.
Any suggestions gratefully received.
I thought I'd cured this issue by replacing the HT setup but it turns out I haven't.
I've so far replaced
Dizzy cap
HT leads
Ignition Amp
Spark plugs
Fuel
The Griff is in the wrong garage so I went to move it last night to its cozy home for the winter but it clearly has other ideas.
Here is what happened last night
Disconnect Accumate
Unlock car
Turn key so I can hear fuel pump (Its a habit)
Start
Lovely V8 rumble
Runs for about 30 seconds to a minute then dies. No cough, not running rough, just idling then dead, and it won't restart although I can hear the pump priming.
This morning I followed the same procedure and it won't start.
It turns over and over and over but makes no attempt to start.
The last time it did this I left it for a couple of weeks and it started first time. And about 5 times more, so I took it for a pootle down the road and back - maybe 2 miles or so - and popped it into Mrs B's garage as she was away.
Because of the way it dies and won't restart I'm beginning to think it might be the alarm killing the system, so I need to bin the alarm and get a new one, but have no idea how to test this.
I replaced the alarm a few years ago with one which was a straight plug-in replacement, which I detailed in the Griffith Parts List so I now know it was replaced Nov 2014
http://abacuscaralarms.co.uk/alarmshop/index.php?a...
I'll disconnect the battery tonight and leave it a few days then try again but I wondered if there was another way of testing for a dead system which might tell me the alarm is shutting something off.
Any suggestions gratefully received.
Edited by Barreti on Wednesday 30th November 12:28
Check battery voltage - should be 12.5 to 12.8 much less and it will not start
Check Fuel .. obvious but you would be amazed how many of us get caught out by that one
If it fails to restart - spray easy start direct into the plenum (remove air pipe) if it restarts
then you know you have a fuel and not ignotion issue.
Check Fuel .. obvious but you would be amazed how many of us get caught out by that one
If it fails to restart - spray easy start direct into the plenum (remove air pipe) if it restarts
then you know you have a fuel and not ignotion issue.
Could be lots of things, like a loose king lead, blocked fuel rail, rat in the air intake, not speaking nicely to it, immobiliser issue, etc etc. Needs to be tackled logically, then trailered to an expert when we cannot solve it.
I am 20 miles from you, have a trailer, and my TVR is in pieces, so not available for play. Would it help if I popped over at the weekend to try to sort it with you? I do have a proper jump start pack, multimeter and spanner set...
I am 20 miles from you, have a trailer, and my TVR is in pieces, so not available for play. Would it help if I popped over at the weekend to try to sort it with you? I do have a proper jump start pack, multimeter and spanner set...
I've checked the spark and its OK
I replaced the entire HT lead set including king lead because I wasn't happy lead 4 was sealing correctly
There is fuel at the rail and wet plugs after turning it over so I guessed the fuel rail was OK
I have to admit I haven't pulled the air intake and searched for rodents but this isn't rough running. It starts then it dies. Just like it would if I'd removed the key. Then it won't start.
If worst comes to it I'll get it over to James Agger so I might yet take you up on your very kind offer of the trailer QBee, but there is a way to go yet before I give in and go there. I'm a pretty competent mechanic but the way this just switches off and won't restart has me foxed
I replaced the entire HT lead set including king lead because I wasn't happy lead 4 was sealing correctly
There is fuel at the rail and wet plugs after turning it over so I guessed the fuel rail was OK
I have to admit I haven't pulled the air intake and searched for rodents but this isn't rough running. It starts then it dies. Just like it would if I'd removed the key. Then it won't start.
If worst comes to it I'll get it over to James Agger so I might yet take you up on your very kind offer of the trailer QBee, but there is a way to go yet before I give in and go there. I'm a pretty competent mechanic but the way this just switches off and won't restart has me foxed
have you got an old working coil you could try, I once had a bike that I'd get a good spark when kicking it over but only by pushing it and watching the spark did I find it stop after a short time.
When you do your spark test do it for a good few engine cycles to be sure the spark is consistent.
Once you've established it's got a spark,
Fuelling and timing + Ecu reader checks need to be done.
Take the cap off the fuel tank,
Clean plugs.
Once you've been turning it over for a long period you may be washing the bores, disconnect fuel pump relay
With plugs removed and a booster pack or extra battery turn engine over with throttle wide open, as much as remove any more fuel your now trying to build up some oil around the pistons and on the bores, flooding as you may well know causes a loss of compression, it will not start until that compression has been built up, can take a lot of cranking.
The instant loss of the engine does make it harder to detect, more like electrical than fuel but you just have to check everything systematically.
I has an instant loss of engine on the Tiv, the small wiring connections to the coil were loose.
Start with the obvious etc
Goodluck
About 6 months ago my fuel gauge said over 1/4 tank and car was running fine, stopped for a few minutes, car wouldn't start, parked at a slight angle, fetched some fuel in a can and it fired instantly, if your tank had less than two gallon in it put some more in.
Just re read your post, ignore most of this!
Hmmm, why do you suspect the alarm.
When you do your spark test do it for a good few engine cycles to be sure the spark is consistent.
Once you've established it's got a spark,
Fuelling and timing + Ecu reader checks need to be done.
Take the cap off the fuel tank,
Clean plugs.
Once you've been turning it over for a long period you may be washing the bores, disconnect fuel pump relay
With plugs removed and a booster pack or extra battery turn engine over with throttle wide open, as much as remove any more fuel your now trying to build up some oil around the pistons and on the bores, flooding as you may well know causes a loss of compression, it will not start until that compression has been built up, can take a lot of cranking.
The instant loss of the engine does make it harder to detect, more like electrical than fuel but you just have to check everything systematically.
I has an instant loss of engine on the Tiv, the small wiring connections to the coil were loose.
Start with the obvious etc
Goodluck
About 6 months ago my fuel gauge said over 1/4 tank and car was running fine, stopped for a few minutes, car wouldn't start, parked at a slight angle, fetched some fuel in a can and it fired instantly, if your tank had less than two gallon in it put some more in.
Just re read your post, ignore most of this!
Hmmm, why do you suspect the alarm.
Edited by ClassiChimi on Wednesday 30th November 17:20
Edited by ClassiChimi on Wednesday 30th November 17:34
Barreti said:
Coil is a good shout ClassiChimi, I have a spare and I can give all the wiring a good fettle while I change it over.
I'll see if I can get to have a look at it tonight but its stuck outside until I can get it to run a bit and move it and its chuffing freezing out there
Nightmare, very good torch or leave it until it's warmer. These damp conditions won't help fuel evaporation, does the engine smell of fuel,,, it should do? I'll see if I can get to have a look at it tonight but its stuck outside until I can get it to run a bit and move it and its chuffing freezing out there
I do appreciate you've got fuel at the rail, but have you thought of your pump/its electric connections,the filters (inline/intank) and a collapsed inner mantle of a fuel line ? I do know the foregoing is a pita job, so best to save for 'last'.
Also, cooland and fuel sensors checked ? (allthough this would cause rough running, not stalling)
Also, cooland and fuel sensors checked ? (allthough this would cause rough running, not stalling)
Lots of possible issues - some good suggestions too.
Bear in mind these engines heavily overfuel on cold start & the engine will tolerate running stupidly rich on startup....less so as the chambers start to warm up. A duff coolant temp sender (or connection) could be giving an artificially low temperature reading & hence cause the fuelling to be even more heavy. As the plugs start to foul there is a point that it will cut out fairly quickly - fancy iridium / platinum plugs are not very tolerant in this scenario...especially when the gaps are on the big side to use the benefit which these plugs can offer. This in itself puts more demand on the ignition system side anyway (I've seen rotor arms track internally causing a cutout / non start). As has been mentioned a spark in open air doesn't mean you get a spark under pressure in the cylinder.
Easy start is most likely the most rapid diagnostic tool in this case...
I hate these types of issues! You almost hope that it will just fail & at least you can root cause it!
Good luck.
Stew.
Bear in mind these engines heavily overfuel on cold start & the engine will tolerate running stupidly rich on startup....less so as the chambers start to warm up. A duff coolant temp sender (or connection) could be giving an artificially low temperature reading & hence cause the fuelling to be even more heavy. As the plugs start to foul there is a point that it will cut out fairly quickly - fancy iridium / platinum plugs are not very tolerant in this scenario...especially when the gaps are on the big side to use the benefit which these plugs can offer. This in itself puts more demand on the ignition system side anyway (I've seen rotor arms track internally causing a cutout / non start). As has been mentioned a spark in open air doesn't mean you get a spark under pressure in the cylinder.
Easy start is most likely the most rapid diagnostic tool in this case...
I hate these types of issues! You almost hope that it will just fail & at least you can root cause it!
Good luck.
Stew.
Hi chaps,
Thanks for your continued support.
I suppose I should have said at the outset my Griff is a 4.3 precat. In case it makes any difference.
I do have the Steve Heath tester though for the life of me I can't remember its name. But I don't have Rovergauge.
Anyway, it isn't showing anything abnormal and no ECU errors.
I have changed the Ignition Amp for a brand new one. I thought this was the issue the first time it happened as I've had this fail before but usually it 'fixes' itself when it cools down so the cutting out only tends to happen when the engine bay is very hot.
I have also changed both fuel relays.
I'd forgotten I haven't changed the rotor arm because I couldn't get it off.
So swap that and change the coil over and check its wiring will be my next call.
I was thinking it might be the alarm because of the way it suddenly dies without getting lumpy or anything, then turns over without a hint of firing.
I can hear the pump running at prime but not when the engine is running because of the exhaust noise. Wasn't there a trick for showing when the pump has power with a light attached to it?
It was a late night at work last night so no chance to get into the garage. So it looks like it will be the weekend now.
Thanks for your continued support.
I suppose I should have said at the outset my Griff is a 4.3 precat. In case it makes any difference.
I do have the Steve Heath tester though for the life of me I can't remember its name. But I don't have Rovergauge.
Anyway, it isn't showing anything abnormal and no ECU errors.
I have changed the Ignition Amp for a brand new one. I thought this was the issue the first time it happened as I've had this fail before but usually it 'fixes' itself when it cools down so the cutting out only tends to happen when the engine bay is very hot.
I have also changed both fuel relays.
I'd forgotten I haven't changed the rotor arm because I couldn't get it off.
So swap that and change the coil over and check its wiring will be my next call.
I was thinking it might be the alarm because of the way it suddenly dies without getting lumpy or anything, then turns over without a hint of firing.
I can hear the pump running at prime but not when the engine is running because of the exhaust noise. Wasn't there a trick for showing when the pump has power with a light attached to it?
It was a late night at work last night so no chance to get into the garage. So it looks like it will be the weekend now.
Edited by Barreti on Thursday 1st December 09:24
Being a precat, a lot of the useful diagnostic information will be missing from the ECUmate as it has no lambda feedback, so it cant tell if the fueling is wrong. Check the ECUmate manual, but id expect there to be an indicator for the pump running, and you can also force the pump on constantly. The ECU needs a steady stream of ignition pulses from the LT side of the coil to keep the pump running, so if you loose that the pump will stop in a couple of seconds. There is a feed wire with a dropper resistor in the loom that feeds the ECU this pulse. How can you tell the spark is OK at the point the engine has died? A colourtune is the only way I know of observing the spark inside a running engine? Are you saying I can see a spark as I turn the engine over on a spare plug but it wont start? If its cranking and not starting, the pump should be running all the time if the LT side is OK. If it always restarts the dies, Id be possibly looking at fuel delivery, something as simple as debris in the tank getting drawn up and blocking its outlet. When the engine dies the debris drops away and the engine will start again. Bit of a problem to detect this as you would want to measure the fuel pressure, and thats not easy on a precat as it has no pressure take off point, unlike the serp engine. What does the rev counter do as the engine dies- does it drop to zero instantly or slow as the engine dies (run an elevated idle for this). An instant drop indicates a loss of ignition trigger.
Thanks for the information Blitzracing. You're correct there is a function of the ECUMate (thankyou) to switch on the fuel pump. I'd forgotten this.
Honestly, I have little information about the details of how the car dies. I've not been inside it when its happened. Its like a ruddy pantomime where I turn my back and it dies
I need to spend time investigating this. I have no idea if the run time is the same before it dies or if its different. That may be a clue.
I'm fairly sure it isn't dirt in the tank because there is no cough or slow down of the engine, it just dies dead.
One other answer, I checked for a spark by pulling a plug lead and attaching it to another plug then turning the engine over. I can see a spark but there is no indication the car has a spark on any other plug, but as the whole HT setup apart from the coil and rotor arm has been replaced with known good items I'm assuming there is a spark around all 7 other plugs.
And finally. The engine right now is dead. It died on Tuesday evening and wouldn't restart. I put it back on the Accumate and walked away. Yesterday I unhooked it and tried to restart it. It turned over but doesn't start.
The last time it did this I had everything apart to replace the HT side and plugs. Then it started and started every time after so I patted myself on the back for being a genius and left it until I got the garage cleared ready to move it back for the winter.
So Tuesday was a shock.
And now I'm not its biggest fan at all and the only thing stopping me beating it with a stick every time I walk onto the drive is my pig headed stubborn attitude that it won't defeat me.
Honestly, I have little information about the details of how the car dies. I've not been inside it when its happened. Its like a ruddy pantomime where I turn my back and it dies
I need to spend time investigating this. I have no idea if the run time is the same before it dies or if its different. That may be a clue.
I'm fairly sure it isn't dirt in the tank because there is no cough or slow down of the engine, it just dies dead.
One other answer, I checked for a spark by pulling a plug lead and attaching it to another plug then turning the engine over. I can see a spark but there is no indication the car has a spark on any other plug, but as the whole HT setup apart from the coil and rotor arm has been replaced with known good items I'm assuming there is a spark around all 7 other plugs.
And finally. The engine right now is dead. It died on Tuesday evening and wouldn't restart. I put it back on the Accumate and walked away. Yesterday I unhooked it and tried to restart it. It turned over but doesn't start.
The last time it did this I had everything apart to replace the HT side and plugs. Then it started and started every time after so I patted myself on the back for being a genius and left it until I got the garage cleared ready to move it back for the winter.
So Tuesday was a shock.
And now I'm not its biggest fan at all and the only thing stopping me beating it with a stick every time I walk onto the drive is my pig headed stubborn attitude that it won't defeat me.
Edited by Barreti on Thursday 1st December 16:40
Gassing Station | Griffith | Top of Page | What's New | My Stuff