Truck revs high at start up then back down but isnt a smooth idle. Will idle better when i put it in neutral .cleaned MAF, and maybe helped a little. Was in the car wash today and it even quit while idling so rough.. ANy ideas?

 

Well, I cleaned the Air idle Control valve and it seemed to help some also. The truck seems to idle fine in park or nuetral. But when i am in gear at a stop it will idle a bit higher than normal, if i give the throttle a tap it goes back down and runs better but idle right back up and a secong or two later.... I am thinking i may need a new AIC? Any ideas?

 

I have had issues like this, but my cause was a blown fail-safe thermostat which was stuck open and was causing the engine to idle higher because it was not warming up properly causing it to be stuck in cold start mode. I don't have any ideas except to check to make sure there are no vacuum leaks.