My car revs up to like 4000rpms when it starts. WHY??

[Poose22]

this happens on occasion and i have no idea why it does this. when i start my car, it sometimes revs up to like 4000rpms for no reason, then goes back down. i dont know why it is doing this. and a lot of times when the car is idling, it will be around 1000rpms. does anyone know the reason behind this? my car is a 1995 grand prix se if you need to know. thanx

[richtazz]

I would bet your IAC valve is sticking.

[hillbilly bryan]

Originally Posted by Poose22

this happens on occasion and i have no idea why it does this. when i start my car, it sometimes revs up to like 4000rpms for no reason, then goes back down. i dont know why it is doing this. and a lot of times when the car is idling, it will be around 1000rpms. does anyone know the reason behind this? my car is a 1995 grand prix se if you need to know. thanx

you need MAF SENSOR

[Ridenour]

For sure either MAF, TPS, or IAC motor.