04 grand prix starting problem urgent!!

truck150 · #1 03-18-2007, 02:34 PM

The car has 40K and has been sitting for about 4 months. I just bought it and everything seemed fine. But about everytime that you start it after it has been running or you have been driving it for awhile, it will start and stall right away. Then if you try it again it just keeps turning over. But if you push the gas pedal to the floor and hold it there and then try to start it again it starts up, then you let your foot off the gas and it stays running, and is fine. Any ideas? i already changed the air filter.

richtazz · #2 03-19-2007, 09:44 AM

any CEL (check engine light) on, if so, what codes are stored?

truck150 · #3 03-19-2007, 08:00 PM

no engine light and i pluged my scanner in and it also had no codes

truck150 · #4 03-22-2007, 08:26 PM

2 days ago i took the throttle body apart and there was alot of carbon build up. so i cleaned it out really good and i haven't had any problems since. could that have been the reason for the bad starting? and what would cause a lot of carbon build up? could it possibly be o2's going bad that would make the build up? hopefully someone can give me some answers. thanks for the help in advance.

guitarfish · #5 03-22-2007, 11:10 PM

Say, did your throttle body look anything like the one I did 2 weeks ago, in my thread? Mine had 160K. I bet you didn't snap bolts like I did, LOL.

I don't know why all that carbon builds up there, but it sure is gummy & nasty.

04grandprix_blows · #6 05-27-2007, 05:10 PM

Quote:

Originally Posted by truck150

The car has 40K and has been sitting for about 4 months. I just bought it and everything seemed fine. But about everytime that you start it after it has been running or you have been driving it for awhile, it will start and stall right away. Then if you try it again it just keeps turning over. But if you push the gas pedal to the floor and hold it there and then try to start it again it starts up, then you let your foot off the gas and it stays running, and is fine. Any ideas? i already changed the air filter.

I have the same problem. If it sits for a few a while (8 hours), it starts fine. When I restart it after any where from 5 min - 3,4 hours, it dies. So I always start it while pressing on the gas a little bit, it's the only way to get it to go. Seems that this is a Pontiac issue that has never been fixed. We took it to the dealership, they said they had to replace some $100 part. Haven't done that yet...will try to clean it out any build up first.

frekey · #7 05-27-2007, 07:30 PM

i think we can blame the buildup on the EGR system. I dont like the thought of exhaust entering my manifold to be re-burned.

Damnir · #8 05-29-2007, 08:28 PM

I had the exact same issue as you truck150. I had carbon build up that was causing my car to stall immediately if I didn't give it gas while turning it on. My mechanic used a solvent to dissolve it, and it's been flawless ever since. I was quoted by the dealership I needed a new fuel pump, running approx $800.00. Are all dealerships this shotty at repairs? It's sad to say I have better service from CANADIAN TIRE!

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