Hi there,
Jeep Grand Cherokee 2000 4.7
I am trying to help my electrician figure out what could be the issue with the engine’s unstable idle speed and then stalling when warm eventually.
Long story short, I took car to the electrician because the car didn’t want to start for most of the time (when the engine was warm mostly). I needed usually to remove and put back back battery cables, then it would reset and start straight away. So the electrician had an idea. He added his custom-made module, which did reset everytime something in the ECU and then the engine could start easily. Then after a few days, a sudden issue with idle arose. (even when we removed that module it didn’t fix the idle issue)
When the engine is cold idle starts to go up and down (by a fraction) and then when the engine reaches operating temperature and when I stop (either in the drive mode or parking) the engine just dies. Not all the time, but I would say 80%.
When the car is in parking and the gas is pressed a bit to keep (rpm) up, the engine won’t die.
Following things have been changed so far (some things twice to be 100% sure it is not the sensor)
-camshaft sensor (twice)
-crankshaft sensor (twice)
-tried another ECU (we thought that this was the issue for starting and idle but it wasn’t)
-idle air control valve (electrician cleaned that, but we didn’t replace to a new one)
Following things that we could try:
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We are thinking to replace wires to the camshaft and crankshaft sensor, perhaps that could be the issue?
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Not sure but perhaps MAF (mass airflow) sensor should be replaced as well?
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Also thinking to replace the ‘idle air control valve’ with a brand new one.
What are your ideas guys, what should we do next? I am not worried that much about the engine starting issue (since the module can fix that) but the idle issues are the biggest issues right now.
Thank you for your time!