rockfangd Posted October 2, 2009 Report Posted October 2, 2009 Ok so I am having trouble with cold starts. Every cold start it starts then stalls like the idle is too low. What I have to do is hold down the gas a little and then it starts. As soon as it is running I can let go of the pedal. I have no problems with warm starts. I have changed the IAC, and tried the idle relearn with no help. Does anyone know if the idle relearn is different on the 2000 lumina than my 94 cutlass supreme? Quote
Imp558 Posted October 3, 2009 Report Posted October 3, 2009 I didn't know there was an idle re-learn on either one? Learn something new every day! The GM Ecotec engines have this problem because the throttle body gets dirty fast, but it's really only the DBW cars that suffer from it the most. I'd get in there and scrub it out and then start looking towards the TPS. Quote
89SupremeCutty Posted October 3, 2009 Report Posted October 3, 2009 have you tried to clean the maf sensor at all? Quote
rockfangd Posted October 3, 2009 Author Report Posted October 3, 2009 have you tried to clean the maf sensor at all? No I will have to pick up some cleaner and try it tomorrow. Thanks I didn't know there was an idle re-learn on either one? Learn something new every day! The GM Ecotec engines have this problem because the throttle body gets dirty fast, but it's really only the DBW cars that suffer from it the most. I'd get in there and scrub it out and then start looking towards the TPS. The top end is like new because I thoroughly cleaned and replaced everything that could be an issue. So TB is like new. IAC ad TPS are also new Quote
rockfangd Posted November 6, 2009 Author Report Posted November 6, 2009 ok so here we are with winter fast approaching and this problem is worse than ever. I still cannot get the car to start on its own on a cold start. I replaced the IAC , TPS, MAP, CTS, performed multiple idle relearn procedures. Everything i have done has made no difference. I also inspected all lines for leaks and found nothing I dont know if this will help anything but what I did was plugged in a scantool and pulled up the IAC controls and started the car, The car was idling around 725rpm and when i commanded the IAC to raise the idle to anything higher or lower it would not change the idle more than 25rpm. when you command the IAC to raise or lower idle it is supposed to react almost immediately so I am baffled. Once the car is running from the cold start I can restart it all day as long as it doesnt set for too long. Is it possible that the MAP sensor on the intake. Or the mass air flow sensor could be faulty. I dont know i have never had this much of an issue, usually the IAC solves the problem. Also NO SES LIGHT Quote
SigEpCutlass Posted November 6, 2009 Report Posted November 6, 2009 Did you get the IAC from the parts yard, or the store? If you got it from the store I would take it back for another one. Quote
rockfangd Posted November 6, 2009 Author Report Posted November 6, 2009 well first I tried a used one and now i have a new one, and there is no difference Quote
Brian P Posted November 6, 2009 Report Posted November 6, 2009 Do you remember offhand what the step-readings were for the IAC at regular idle? I'm tempted to say MAF sensor problem where it reads incorrectly, but not enough to set the light. Is the small hole in the throttle plate clean and free of buildup? Other issues could be a loose vacuum line, leaking throttle body gasket, loose breather hose and/or leaking intake hose. Any leak after the MAF will cause some issues and will be most apparent on a cold start. Quote
rockfangd Posted November 10, 2009 Author Report Posted November 10, 2009 Ok so on top of everything ele i have done i cleaned the MAF and the TB looks like new, still having the same issue Quote
Brian P Posted November 10, 2009 Report Posted November 10, 2009 have you reset the computer and allowed a relearn? Quote
rockfangd Posted November 11, 2009 Author Report Posted November 11, 2009 I have pulled the pcm fuse from the pass side fuse box, and tried about 3 times, I really wonder though if the idle relearn is different on this car. It seems that when the air pump kicks on which is on every cold start, it has trouble staying running. Maybe related, maybe not. Im crazy Quote
Brian P Posted November 12, 2009 Report Posted November 12, 2009 well it's not so much an idle relearn, more like an emissions/sensor relearn. Quote
rockfangd Posted November 12, 2009 Author Report Posted November 12, 2009 ok so tonight i tried to change idle with the scantool again and still have the same problem. Could the pcm be the issue? Quote
rockfangd Posted November 24, 2009 Author Report Posted November 24, 2009 well Iam still having this issue still have not figured anyhing out. I am starting to think maybe ECM is the fault Quote
rockfangd Posted December 13, 2009 Author Report Posted December 13, 2009 Well I do believe I have narrowed this down to a possible vacumn leak at the rear of the engine but nothing is visibly cracked, broken, seperated, etc... I hooked up a vacumn pump and it holds no pressure at all when it is cold. Does anyone have any recommendations on how to trace this problem? seems to me there is some kind of solenoid at the rear of the engine that has 1 vacumn line going into it and 1 coming out that Tees off around the driver side of the engine Quote
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