Hot start problem - again
Discussion
I have a 4.0 Griff that refuses to start when hot. It starts like a dream from cold but after more than 10 minutes or so of driving the starter turns the engine but the car does not fire up.It's a little embarassing at petrol stations!
but.. if I keep my right foot planted into the carpet it will re-start, some times the revs remain high and there's always loads of smoke from the exhaust.
Any ideas where I should start looking?
but.. if I keep my right foot planted into the carpet it will re-start, some times the revs remain high and there's always loads of smoke from the exhaust.
Any ideas where I should start looking?
Well at least that isn't the usual cooked starter motor then!
I would suspect either fuel evaporation in the fuel rails, or some electrical component breaking down in the heat - coil would be the first suspect. Traditionally you would track this down by getting it to fail and then going round with a bag of frozen peas cooling things down until it started. For instance if you find it usually restarts promptly after you've cooled the coil down, there's your problem.
I would suspect either fuel evaporation in the fuel rails, or some electrical component breaking down in the heat - coil would be the first suspect. Traditionally you would track this down by getting it to fail and then going round with a bag of frozen peas cooling things down until it started. For instance if you find it usually restarts promptly after you've cooled the coil down, there's your problem.
This could be a bit of overfuelling on cranking. There is a cold start injector mounted directly on the plenum chamber. Try removing this, I have been told that it is only ever needed below -10 degrees centigrade. On my 390 this is permanently disconnected.
Other than this try the block temperature sensors.
The cold-start regime of the V8 gives extra pulses of fuel from the cold start injector for the first 12 to 14 seconds of cranking so if you just dab continuously at the starter you will wet your plugs.
Other than this try the block temperature sensors.
The cold-start regime of the V8 gives extra pulses of fuel from the cold start injector for the first 12 to 14 seconds of cranking so if you just dab continuously at the starter you will wet your plugs.
Thanks for the pointers. As the problem happens all the time it's easy enough to replicate and try different things until it starts.
I'll try the frozen peas but that wouldn't explain why it starts if I keep the accelerator full on while cranking. (when it does start there's usually a fair amount of smoke). I suspect over fuelling or low fuel pressure.
How many temp senders are there on the Griff? Any idea where they're located and can where can I source new ones from? Is it a Lucas part?
I'll try the frozen peas but that wouldn't explain why it starts if I keep the accelerator full on while cranking. (when it does start there's usually a fair amount of smoke). I suspect over fuelling or low fuel pressure.
How many temp senders are there on the Griff? Any idea where they're located and can where can I source new ones from? Is it a Lucas part?
turtle400 said:I'll try the frozen peas but that wouldn't explain why it starts if I keep the accelerator full on while cranking. (when it does start there's usually a fair amount of smoke). I suspect over fuelling or low fuel pressure.
Wouldn't overfuelling get worse with the throttle full open? Fuel evaporation sounds more likely...
Page 89 in Bible 2. One temp[ sensor for ecu located at front of engine next to the alternator. Second sensor nearby is for the temp guage.
No cold start injector. Any enrichment is done automatically by the ECU.
Lucas bit about £12-15.
If you need open throttle then the car is overfuelling or running rich which could be caused by no end of things. The temp sensor is just one of them and could include duff air flow meter, leaky injectors, duff ECU and so on. Worth getting a fault reader onto the ECU to see if it reports a fault. Big danger of sopending a lot of money replecing the injection system. If nothing obvious, worth calling in the professionals.
Steve
www.tvrbooks.co.uk
No cold start injector. Any enrichment is done automatically by the ECU.
Lucas bit about £12-15.
If you need open throttle then the car is overfuelling or running rich which could be caused by no end of things. The temp sensor is just one of them and could include duff air flow meter, leaky injectors, duff ECU and so on. Worth getting a fault reader onto the ECU to see if it reports a fault. Big danger of sopending a lot of money replecing the injection system. If nothing obvious, worth calling in the professionals.
Steve
www.tvrbooks.co.uk
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