PontiacBonnevilleClub.com

Hey everyone, it's been a long time, but I've been caught up in school and stuff. I know this is for a Grand Prix but I can't get decent help anywhere but here...

Symptom: On a cold start, car will be hesitant between 1-2.5k rpms (feels kinda like a misfire), and the 1-2 gear shift seems to come about 1k late, and when it does shift, it IS NOT smooth. If I go WOT I will hit the rev limiter before it has a nasty shift.

Transmission problem? Not at all. If I restart the car, EVERYTHING IS JUST PERFECT - runs flawlessly. To make this more rediculous, this only happens in cold weather. This will never happen during the summer.

- If the car doesn't get cold between restarts it won't happen.
- If it does happen on a cold start, it doesn't matter when the car gets restarted. I can drive it for 2 seconds, notice the problem, throw it in neutral, and restart it. All is fixed.
- Again, never happens in warmer temperatures.
- I had a non-insulated garage space for 4 days, and it got cold out. It never happened for the 4 days. (moisture thing?)

The best part is, I have brought this issue up on several Grand Prix forums, and other people said they had the SAME problem, yet no one had a solution.

One guy said he replaced his PCM and it stopped happening...but thats about it. Help meeeee!

I was going to just lean towards PCM when I started reading this before hitting the end.....Sounds to me like it could POSSIBLY be related to your cold-loop mode programming. Defaults for the car before it warms up. Why resetting 2 seconds after starting would get it out of that while still cold is beyond me...but it's a possibility. I'm no expert. Disconnect your battery for 10 minutes and let the computer empty. See how your car runs after that from dead cold and after that.

Is your PCM somewhere you can wrap it in a towel and a plastic bag? I'm thinking about keeping out moisture... If they get hot, unwrap it after you start it and see if the behavior changes any.

Thanks for the suggestions. The PCM is exposed, it used to be part of the airbox assembly but I have a FWI installed. This problem happened just like it did before I removed from the airbox, so that isn't the problem.

I will try wrapping it something...that is a good idea. Are PCM's typically something that get really hot on thier own? The whole thing is like a giant heatsink, so maybe the heat dissapation is good enough to wrap it in something.

I will try disconnecting the battery, but the car has been disconnected several times in the past when I've been working on it. What does cold-loop mode programming entail?