Redfox340 Posted March 3, 2003 Report Share Posted March 3, 2003 Ok, I'm thinking an idle re-learn is needed or something very little. Read over and see what you guys think... perhaps a sensor or ECM? Help! 95 Lumina with 3.4 DOHC with 105,000 miles. Recently purchased and trying to get into shape but encountering one costly problem after another. Latest is at colds start, car runs ok until it warms slightly and my neighbor says the computer comes on line. Then the idles speed starts wavering up and down. The high end is 1600-1800 rpms then down to 200-400. Finally the car with stall at the low end. Also seems to have lost power. Had it on scan tool (neighbor again) and it is throwing no codes. Performed test on fuel regulator and increasing fuel pressure does not help. Recent maint: O2 sensor timing belt fuel filter fuel pump Idls Speed Motor Intake Manifold Gasket (yes this fixed an earlier cold start idle problem) The "Closed Loop" effect is known to me, and what he getting at is that something related to regular running outputs is effecting the car... besides emissions, what else could it be? Thanks guys!!! - RedFox340 Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted March 3, 2003 Report Share Posted March 3, 2003 When I broke my MAP sensor line, the car would do that. Idle when it was cold, then when it warmed up and the MAP started controllin idle more, it would do try to stay running at low RPMs and then die. But, I dont think the LQ1 had a MAP, so that wouldnt work. What about the IAC?? or MAF?? If none of those work, try an idle relearn, then if that doesnt get it, maybe a new PCM But that sounds like a vacuum leak somewhere..... Robby Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 5, 2003 Author Report Share Posted March 5, 2003 Thanks for the look. This is getting expensive. I took the car in to the local Chevy dealer and they can't find the problem after a day of looking.Their best guess is the manifold gasket was torqued to much and it's leaking again. I then pointed out the symptoms are entirely different from what was experienced before the gasket was replaced. Any ideas? Well... now what? I recommended the gasket leak-test with some carb cleaner and he'll get back to me. Howver, if the gasket is over-torqued, wouldn't that still produce a high-idle at cold starts? - RedFox340 Quote Link to comment Share on other sites More sharing options...
sdoDrew Posted March 11, 2003 Report Share Posted March 11, 2003 soudns like mine. Idle relearn fixed it. Quote Link to comment Share on other sites More sharing options...
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