02 Grand Cherokee idle problem
#1
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Join Date: May 2014
Location: Michigan
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Year: 2002
Model: Grand Cherokee
Engine: 4.7L V8 Power Tech HO
02 Grand Cherokee idle problem
When I'm driving, even though I'm holding the accelerator steady, the engine idle speed will increase and then decrease. The change in idle seems to cause the transmission to downshift sometime at around 60mph, while driving on the expressway. It seems to idle high when the engine is cold and will increase and decrease idle speed a lot. What would cause this?
#2
Old fart with a wrench
Welcome to CF!
Two things off the top of my head. Check your IAC (idle air controller) and the hose to your MAP (manifold air pressure) sensor.
Is this a 4.0 or a 4.7 V8?
Two things off the top of my head. Check your IAC (idle air controller) and the hose to your MAP (manifold air pressure) sensor.
Is this a 4.0 or a 4.7 V8?
#3
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Year: 2002
Model: Grand Cherokee
Engine: 4.7L V8 Power Tech HO
#4
Old fart with a wrench
Okay, I'm a little out of my league here. I've owned a couple of 4.0s, but haven't even been in the presence of a 4.7. In all honesty, I couldn't tell you where to look except to check those things.
#5
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Year: 2002
Model: Grand Cherokee
Engine: 4.7L V8 Power Tech HO
Just got this Jeep and haven't had much time to look around at it much. Well, your idea about the hose to the MAP helped and it turned out to be a simple fix. The clamp was loose at the throttle body intake. Tightened it up and that fixed the problem. Not sure what normal is for this engine but seems like it's idling more normal now. Thanks for your help!
#6
Old fart with a wrench
Glad to help. My 4.0 starts cold at 1000 and then settles down to 750.
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