Topbiker49 Posted March 1, 2012 Report Share Posted March 1, 2012 Yesterday I was going to visit friends and after driving about 60 miles I stopped at a Harley dealership. When I put the car in park the engine raced up to 2 grand and stayed there. I turned the car off and when I restarted the car about 15 minutes later it was still idling at 2000RPM. It created quite a clunk when I shifted into gear. I got to my friends place and it still idled at 2000RPM. After visiting 5-6 hours I started the car it was normal, idling around 950RPM. Driving home I again had occasion to stop and the car did the same thing, the engine idled at 2000RPM. When I got home I checked for any codes but nothing showed up. Any ideas?? thanks, John Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted March 1, 2012 Report Share Posted March 1, 2012 My 1992 Lumina 3.4 had a similar problem. It sounds to me like your Idle Air Control valve might be sticking/dying. Mine died a very abrupt death which resulted in my trip home being between 70-75mph with my foot off the throttle. Idle air control valves are pretty universal on GM V6s...my replacement came off of my old 3100 powered 1994 Grand Prix, and solved my issue. You can try cleaning yours with something like throttle body cleaner or brake kleen, but once you've got it off, you might as well replace it with a new/known good one. You could also have an intake manifold gasket that's leaking, but that usually results in an idle that is continuously high, and doesn't revert back to being normal. The impromptu way I checked for a vacuum leak (I was 30 miles from home, troubleshooting in a parking lot) was by removing the air box assembly, and sticking my hand directly over the throttle body. My theory was this: If a vacuum leak was causing my high idle, the car would continue to run even with my hand over the throttle body. My engine died immediately, and actually held a vacuum against my hand until I pulled it away. That ruled out a leak, and I was right. Good luck! Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted March 1, 2012 Report Share Posted March 1, 2012 it's also a possibility that the TPS is acting up. should this happen again, shut the car off, wiggle the TPS connector around, pull the ECM fuses for a couple minutes, reinstall and then see if it goes back to normal. Quote Link to comment Share on other sites More sharing options...
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