Poundz9oh9 Posted February 12, 2006 Share Posted February 12, 2006 Hey guys, I got a question. I have a 98 Saturn SL1 SOHC with about 110,000 miles. I'm having some idle issues. Once the engine is road temp, it begins to idle high once you stop at a light. The RPM's go to about 2500 - 3000 and stay that way. What could cause this? I was thinking maybe a sticky throttle cable, but what else could this potentially be? Any help is appreciated guys. Quote Link to comment Share on other sites More sharing options...
Sumo Posted February 12, 2006 Share Posted February 12, 2006 Check your IAC idle air control valve and TPS throttle position sensor. Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted February 12, 2006 Share Posted February 12, 2006 Check your IAC idle air control valve and TPS throttle position sensor. Ditto on the iac and tps. My Civic was bouncing up and down once it warmed up and it was a "fast idle thermo valve" problem. A buddy says the bounce is from the ecu seeing high idle and cutting the injectors off and on to control it. Your ecu may not do that, hence staying at high idle. The Autozone will read your codes on the OBDII systems for free and that may tell you what it is (assuming your check engine light is on). If you don't have an Autozone you may call around to the bigger chains. I diagnosed mine by finding the valve (under the TB) and once it warmed up gently tapping on it with a hammer and it slowly closed. Of course, this was only temporary till it was cold started again. Good luck with it. Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted February 12, 2006 Share Posted February 12, 2006 Once it gets to temp and starts acting up, shut it down and remove the intake hose/box at the throttle body. You should see a hole before the blades on the wall that is your iac bypass route. Crank it up and while idling high, put your finger over that little hole. If its bad and wide open, your engine will almost die. Oh, and when you put your finger over the hole, be ready. Scared me so bad the first time it did it I dang near had to change my shorts. Of course, mine was at 1500 rpm, you may want to find an alternative to the finger with yours at 3000 rpm. Your IAC looks like this http://www.partsamerica.com/ProductDetail.aspx?mfrcode=GPS&mfrpartnumber=77910063&parttype=757&ptset=A later, Quote Link to comment Share on other sites More sharing options...
80LS1T Posted February 13, 2006 Share Posted February 13, 2006 Sounds like your IAC is sticking. If you shut the car off and start it back up does it idle like normal again or is it still idleing high? Quote Link to comment Share on other sites More sharing options...
Okimoto Posted February 16, 2006 Share Posted February 16, 2006 you can jam the IAC and unplug it to keep the idle steady until you get the TPS replaced. My dad's 95 had that same idle problem... so we let the car warm up to normal... then unplugged the IAC. It's not OBD II though, so dont know if it will work on yours. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.