it's no in a fiero although I know you guys can help figure this out. 96 cutlass ciera. when my friends wife starts the car every now and then it starts with a high idle. without touching the pedal she shuts it off and turns It back on and everything is normal. the tsp was replaced about a year ago because but it didn't help. some times it happens when she's on the road. we did a scan and it said tsp. could it be the cruise control(they don't use it) ? or possible the throttle cable? the idle air valve was also replaced. maybe a connector or something? I've never seen it happen. I hope you all don't mind I ask for help on this forum.
The ECM normally zeros the IAC when the key is turned off and then presets it for the next start. I am suspecting that the ECM is having troubles doing that. Since you have replaced the IAC, my next suspect is that there is carbon in the IAC passage that is blocking it from moving freely.
thanks for the reply. we had ryan rechip a matching ecm because we thought that might be the problem. but after a couple of weeks it was back to it's misbehaven. now and then it will keep the rpm up going down the highway even though it didn't do the fast idle ghost at start up. and it will make the tps code.