Galaxie500XL Posted January 14, 2011 Report Share Posted January 14, 2011 My '95 LQ1 Cutlass has suddenly developed some strange drivability issues. I had been having a problem recently with high idle on startup on occasion, but now the car is almost undrivable. No codes are being set, according to my scantool. Temps have been below freezing for several days. When first starting the car, it just sort of "putters" for a few seconds, barely running, then like a switch was thrown, picks up and idles around 1500 RPM. The idle has begun "hunting". Runs for about 3 seconds, drops for a blink of an eye, then idles normally for 3-5 seconds, over and over...but, not all the time. At 55-60 MPH, as long as you are traveling at a steady speed, everything seems fine. Give it a bit of gas approaching a hill, though, and the car begins bucking, until you either let off the gas, or manually drop the car out of overdrive in order to pick up speed. Even when the car appears to be idling normally, sometimes when leaving from a light, the car seems to have no power, and RPM's climb very slowly...then suddenly, it picks up, and feels normal. Fuel filter, TPS, and IAC have been replaced within the past 6 weeks, chasing what began as a intermittent high idle. Again, no codes are being set, and looking at the realtime data on my scantool, I'm not seeing anything that looks out of place. Any ideas? Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted January 14, 2011 Report Share Posted January 14, 2011 LIMG's (easy on a LQ1). Try spraying brake cleaner or quick start around the gasket mating surfaces of the plenum to LIMG and LIMG to heads while idling. See if the revs increase. If so you found your leak. That or a massive vacuum leak. Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted January 14, 2011 Author Report Share Posted January 14, 2011 I had been thinking the same thing about a vacuum leak...the LIMG was changed about 3,000 miles ago. I did find a bad vacuum hose, but no change. I was wondering, though. I replaced the IAC with a new one just before all this started, could the new one be bad, and cause these symptoms? Quote Link to comment Share on other sites More sharing options...
Captain Ficho Posted January 14, 2011 Report Share Posted January 14, 2011 Sounds like what my car did when one of the vacuum line "T" connectors asploded... Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted January 31, 2011 Author Report Share Posted January 31, 2011 Well, it's fixed...bad coil, #2/5. Not much fun to replace, since it's under the exhaust manifold, but it runs like new again! 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.