GMC Repair: high idle 2000 grand am se, throttle positioning sensor, vacuum line

Question
when in park engine revs up to 2000-3000rpm have to turn off car to stop it. sometimes this works sometimes not.
mechanics could not figure out the problem  eventully replaced computer car ran fine all winter now the high idle has returned any ideas.
thanks

Answer
Your problem is most likely within the IDLE AIR CONTROL MOTOR and or an intermittent fault in the THROTTLE POSITIONING SENSOR or it could be a residue buildup within the THROTTLE PLATE AREA.

If you have an intermittent short in the IAC this can cause the computer to fail.

Did the mechanics find any DIAGNOSTIC CODES when they put it on the scanner and what code(s) did they find.

What mechanical work or ANY kind of work has been performed on the vehicle recently ?. As most problems that occur after a recent repair was made can be traced back to the area of where the repair was made as a vacuum line may have been knocked loose or a wire connection came loose, Look around in the area where work was performed..


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