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Q: car surges when idle or in park. rpm bounce. car has cut off, but cuts back on.

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When I am parked or idle (stop light etc) I can feel my car shaking and surging. The RPM bounce. My car also cut out the other day, but cut back on after restarting it. I have had the water pump replaced, a new battery, a new thermostat, and some kind of pulley that was replaced when my car overheated. sorry don't know the exact name as I'm at work. what is wrong with my car? Need help!!!!!!!!!!

My car has 128000 miles.
My car has an automatic transmission.

A: It sounds like your idle air control valve ...

It sounds like your idle air control valve could be failing. The idle air control valve is responsible for maintaining the proper amount of air into the intake while the vehicle is slowing down to a stop and resuming idle speed. When this valve fails, it can cause the exact symptoms that you described. I would recommend having the idle air control valve inspected by a qualified professional to determine if it is performing properly. If the IAC valve has failed, I would recommend having it replaced at your earliest opportunity.

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