Car only runs for 10 seconds...
Discussion
Hi I'm hoping someone can help.
My 2001 Tuscan has started randomly cutting out when running. When it cuts out, I can start it back up again but then it only runs for 10 seconds before cutting out again. When it initially happens it appears to be when the car is hot, ie has been running for around an hour.
The issue seems to go away if I wait for around an hour and then try starting again and it will run fine, then after some time driving, say 30 mins it happens again.
I've read some of the advice on here about the fuel relay and pump, however I dont think its that, as if I pull the fuel pump relay with the engine running, the engine kind of fades away as the fuel pressure drops. With the fault occuring, its a clean instant stop the same as the ignition being switched off. I can also hear a relay click the moment the engine stops, although I guess this may be a result of the stop rather than the cause?
I've dug out the immobiliser (I think that's what it is!) and can't see any corroded terminals or damaged cables.
I've also removed and cleaned the crank sensor but no difference. I imagine if the crank sensor failed I wouldn't get a RPM readout on the display? During the 10 seconds it will run for the RPM is reading fine, and the car can drive until it shuts off.
The coil pack isn't visibly cracked.
I've checked the diagnostics and only a low battery fault has been recorded, probably from when I replaced the old failed battery last year. All sensors show green and healthy.
Could the immobiliser cut the engine when its already running? or does it just cut the fuel and starter motor?
My 2001 Tuscan has started randomly cutting out when running. When it cuts out, I can start it back up again but then it only runs for 10 seconds before cutting out again. When it initially happens it appears to be when the car is hot, ie has been running for around an hour.
The issue seems to go away if I wait for around an hour and then try starting again and it will run fine, then after some time driving, say 30 mins it happens again.
I've read some of the advice on here about the fuel relay and pump, however I dont think its that, as if I pull the fuel pump relay with the engine running, the engine kind of fades away as the fuel pressure drops. With the fault occuring, its a clean instant stop the same as the ignition being switched off. I can also hear a relay click the moment the engine stops, although I guess this may be a result of the stop rather than the cause?
I've dug out the immobiliser (I think that's what it is!) and can't see any corroded terminals or damaged cables.
I've also removed and cleaned the crank sensor but no difference. I imagine if the crank sensor failed I wouldn't get a RPM readout on the display? During the 10 seconds it will run for the RPM is reading fine, and the car can drive until it shuts off.
The coil pack isn't visibly cracked.
I've checked the diagnostics and only a low battery fault has been recorded, probably from when I replaced the old failed battery last year. All sensors show green and healthy.
Could the immobiliser cut the engine when its already running? or does it just cut the fuel and starter motor?
Agreed, you seem to have proved that a fuel pump circuit problem doesn't stop the engine instantly
Suggest that you check the ignition coil supply first
There is an ignition coil fuse in the fusebox, might be worth checking the supply at the fuse before delving deeper
You could wire a test lamp into the ignition coil supply and see if it vanishes when the engine cuts out
Yes the immobiliser could be wired into the ignition circuit
There could be an ignition relay, not sure though as I haven't got the information handy right now, will have in the morning
Suggest that you check the ignition coil supply first
There is an ignition coil fuse in the fusebox, might be worth checking the supply at the fuse before delving deeper
You could wire a test lamp into the ignition coil supply and see if it vanishes when the engine cuts out
Yes the immobiliser could be wired into the ignition circuit
There could be an ignition relay, not sure though as I haven't got the information handy right now, will have in the morning
The fact that it seems to run for a bit and then stops does kinda point to the immobiliser. I would have thought that everything else, once it's gone wrong, would stay like that for a bit and would stop you from restarting it... Yet it's like an ignition off cycle resets it. Is it consistently 10secs? And you can restart it like that multiple times?
OK it seems the immobliser is the right place to be looking, If i remove fuse 27 which is the immob ignition, then it recreates the behaviour I'm seeing, were I can disarm the car, start and it stops after 10 seconds. I think what's happening is the immob isn't seeing that the car has started and re-arms itself, which on my car at least cuts off the ignition.
The drawings I have dont show what's going on inside the fuse panel, only the wiring to it which is annoying! I need to find where the supply for fuse 27 comes from, or perhaps there's a bad contact somewhere along the route or a dodgy relay that overheats.
I think I'm going to rig up a test lamp to fuse 27 and see if that supply is being lost, or if the immobiliser just isn't picking it up.
The drawings I have dont show what's going on inside the fuse panel, only the wiring to it which is annoying! I need to find where the supply for fuse 27 comes from, or perhaps there's a bad contact somewhere along the route or a dodgy relay that overheats.
I think I'm going to rig up a test lamp to fuse 27 and see if that supply is being lost, or if the immobiliser just isn't picking it up.
I had a similar problem with an imobiliser unit
Car would run for 20 mins then die and wouldn't restart - after 5 - 10 mins it would restart and then do another 20 mins
The imobiliser was getting hot and breaking down cutting of the fuel pump - took the unit out and fitted a hidden switch instead
Car would run for 20 mins then die and wouldn't restart - after 5 - 10 mins it would restart and then do another 20 mins
The imobiliser was getting hot and breaking down cutting of the fuel pump - took the unit out and fitted a hidden switch instead
Magicmushroom666 said:
OK it seems the immobliser is the right place to be looking, If i remove fuse 27 which is the immob ignition, then it recreates the behaviour I'm seeing, were I can disarm the car, start and it stops after 10 seconds. I think what's happening is the immob isn't seeing that the car has started and re-arms itself, which on my car at least cuts off the ignition.
The drawings I have dont show what's going on inside the fuse panel, only the wiring to it which is annoying! I need to find where the supply for fuse 27 comes from, or perhaps there's a bad contact somewhere along the route or a dodgy relay that overheats.
I think I'm going to rig up a test lamp to fuse 27 and see if that supply is being lost, or if the immobiliser just isn't picking it up.
Might be worth speaking to Dave Fairclough at www.hf-solutions.co.uk. He should be able to give you some advice over the phone - at least to prove or rule out the immobiliser circuitry.The drawings I have dont show what's going on inside the fuse panel, only the wiring to it which is annoying! I need to find where the supply for fuse 27 comes from, or perhaps there's a bad contact somewhere along the route or a dodgy relay that overheats.
I think I'm going to rig up a test lamp to fuse 27 and see if that supply is being lost, or if the immobiliser just isn't picking it up.
Nick
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