PontiacBonnevilleClub.com

Sorry for off topic but the rest of this site seems to be dead these days and I am desperate for anything that may help.

I'm looking for a little brain picking on my sons car. This thing is driving me nuts. 2004 Grand Prix. starts fine idles fine. Put it in gear and try to drive away and it will die. If you stomp it to the floor it will take off like a streak of *shoot* and pull hard until you let off the gas then it will die again. If you are sitting in park and stomp it to the floor it will rev up and bounce off the rev limiter all day long. Let off the gas and it may or may not idle. if you very very slowly rev it up it will go all the way to the floor and bounce off the rev limiter. If you just rev it up normally it will get to a certain point and just die every time. I have no CEL and no codes to work with. I have good fuel pressure. I have replaced the throttle body, gas pedal, and just because it was 7 years old I tossed in a new battery. I am grasping at straws here. The car isnt really worth taking to GM dealer to diagnose but it needs to get him through the winter before he can aford a new car. I am open to any ideas you guys may have.

Did you try running it with the MAF unplugged?

No I didnt. The car is sitting in his freinds driveway out in the cold and wind 10 miles from home and that thought crossed my mind on my way home tonight but I was froze and almost home so I figured I would try that tomorrow night

Well I stopped on my way home tonight and unplugged the MAF sensor. It started right up and would idle, but as soon as I touched the gas pedal it died no matter how I tried. I hate problems like this. They get expensive fast

On my son's 2000 Bonneville SLE he had a similar problem.
It turned out to be the CPS (crankshaft position sensor).
The weird thing is that the SES light never went on and there were no codes in the computer.
The other thing is that it might be the ICM (ignition control module).
You might want to look at these 2 possibilities.

This car is drive by wire but at this point I am open to anything. Guess a crank sensor is only 10 bux on amazon wont be out much if it dont work

Crankshaft position sensor is a pain to replace only use GM 10456161 or ACDelco 213151.

I have all the tools and a hoist so it should only take a few minutes. We are going to go get it tomorrow night and take it to the shop since it is getting to be a guessing game. I'm just gonna have to bite the bullet and get my duelly out of storage and unload the car trailer and haul it.

May also want to check for a plugged cat.

Thought I would check back. Problem solved. I finally got it hauled to the shop and put the crank sensor in tonight. Well that didnt solve the problem either. Well now I have it in a heated shop with access to WIFI for my scanner so I hook it up and download the cars specs and start checking crap. Still no check engine light at this point either. I start looking at all the parameters and happen to notice that when I would stomp on the gas there would be no change in MAP sensor readings. Well this seems a bit fishy so I jump out and unplug the MAP sensor and it instantly solved the problem. I went out of popped one out of my Bonneville parts car and plugged it in and we are back in business. I have never seen a MAP sensor cause this type of issue. Im just glad it didnt cost any more than it did. I hate breaking out the parts cannon. Well thanks for all the input. Its nice to know there are people out there willing to help.

Awesome. Thanks for posting the solution.