Pontiac Repair: Rough engine idle, pontiac grand prix, vacuum leak

Question
Todd,

I have a 2001 Pontiac Grand Prix SE 3100 series motor, 131,000 miles.  My car idles really rough.  No noticeable symptoms once I am moving, only idling.  EGR valve replaced at 100K, tune-up at 100K, Head gasket at 85K.  No service codes illuminating inside of vehicle.  Possible vaccuum leak, haven't sprayed WD-40 over top the engine yet.  Also sometimes the car starts then stalls out a couple of times in a row, and the rough idle is at its worst when that happens.    

Thanks,
Kyle

Answer
hi Kyle:

with that many miles on it the sky is the limit was to what the issue could be. It's more then likley not a vacuum leak because you woaul have an elevated idle speed. I would look first at the throttle plate and idle control motor to be gummed up with carbon. clean them out/off and then disconnect the battery let it sit dfor a few minutes. hook the battery back up turn the key to run do not start the car let it sit for 30 seconds. turn the key off for 1 minute then repeat the first step turn the keyy of and wait another 30 seconds then start the car that will reset the idle control motor. if this has the original set of spark plugf wires and or spark plugs I would change them just because they are the originals along with the fuel filter for maintnece purposes and try that.