rough idle
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rough idle
do you have any idea what can cause my 99 explorer xlt to have a rough idle on initial start ups?(Its worse in the winter time) And sometime after driving places when i put it in park the truck will cut off. it has the 6 cylinder SOHC if thats helpful. thanks.
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Joined: Jun 2009
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From: Cedar Rapids, IA
Do you have a fuel pressure tester to confirm the fuel pressure is in specification? That would be one item to confirm. It would also be useful to use a scan tool with datastream mode to confirm the Intake Air Temperature (IAT) is reading something reasonable along with the Engine Coolant Temperature (ECT). If you have a vacuum pump such as a Mity-Vac, apply a little bit of vacuum to the EGR valve to see if that has an effect at idle. If not, either the EGR diaphragm is leaking and not opening or the EGR is stuck open some amount. An EGR valve that is not closing at idle is effectively a vacuum leak and can cause a rough idle and/or stalling.
The intake manifold gaskets and PCV elbow would be other rather common sources of vacuum leaks with your engine that could cause symptoms such as what you describe.
Also, when is the last time the truck has had a tune up consisting of at least spark plugs, spark plug wires, a fuel filter, and air filter?
Have you confirmed the condition of the battery recently? A weak or dying battery in a newer vehicle can cause some odd driveability issues.
-Rod
The intake manifold gaskets and PCV elbow would be other rather common sources of vacuum leaks with your engine that could cause symptoms such as what you describe.
Also, when is the last time the truck has had a tune up consisting of at least spark plugs, spark plug wires, a fuel filter, and air filter?
Have you confirmed the condition of the battery recently? A weak or dying battery in a newer vehicle can cause some odd driveability issues.
-Rod
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