hey everyone new to the cavalier scene, but anyways i have a cavalier 2.2 L 5 speed that idles extremely high. no tach but approx 2000-3000 RPM's. changed IAC and checked vacumm hoses no leaks. Help me please!
perhaps your throttle position sensor?
changed the tps too i forgot to add that
no check engine light either
it could still be the Idle Air Control valve. on my old 90, when It started acting up. I would have to run the car until it was warm, unplug and remove the IAC, pull the plunger on it all the way out, reinstall it, then start the car and then plug it in to drive it to the "home" position. though this probably isn't the case with yours, since you just replaced it, as long as you pulled the plunger out before installing it. Also did you check for a leak possibly on the manifold/plenum/TB. hoses being good doesn't necessarily mean there isn't a vacuum leak. also try unplugging the vacuum line from the fuel pressure regulator while the car is off, cap the end of the regulator and plug the hose, then start it and see if the RPM's are lower.
alright ill try that in the morning, i didn't pull the plunger all the way out before i installed it, i figured it was preset. i did pull the hose off of the fuel pressure regulator earlier this afternoon, the car idled higher until i hooked it back up and it dropped probably 500 RPM's not sure as i have no tach but it was a noticeable difference.
also, should i unplug the battery to reset the computer or sensors and such?
resetting the ECM by unplugging the BAT for 5 minutes probably isn't necessary, but I would say it's not a bad idea, either. I'm guessing since you unplugged the regulator, and the result you describe is normal, it probably isn't that. but if you have or can borrow some kind of handheld vacuum pump, you could try inducing an above average amount of vacuum and see how low you can get it. I'm seeing the regulator is around $80, so it isn't worth trying to swap it out, they rarely go bad.
still having the high idle problem, could it be an intake gasket. im clueless ive tried just about everything and this is my daily driver now. so any help or suggestions is greatly appreciated. Thanks.
it seems like the manifold gasket is the most likely culprit. pretty easy to replace, if you have the 2.2. You can get it for under 10 bucks, you get the manifold gasket and the plenum gasket.
yup turned out to be the intake gasket. most of it was blown out under the throttle body. runs great now (approx. 925 RPM's) thanks for the help.
