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2002 Pontiac Grand Prix problem need help!


Sniderd55
06-06-2012, 10:03 PM
Hello, I posted about some car problems I've been having with my Grand Prix GT earlier. I got everything fixed, but there is still one major problem. The car randomly stalls out and the auto shop said they do not know what the problem is. Today I noticed that the rpm's will go out and I was ready for it to stall, but never did. I dont know if that has anything to do with it or not. There are no lights on showing any problems. Can someone give an explanation for this? Please and Thank you!

Tech II
06-07-2012, 06:32 AM
Does it stall more when hot or cold?

When coming to a stop or while cruising?

Does it restart right away?

Does it accelerate OK? Any misfires?

Check for codes?

Check for fuel in vac line to f/p regulator?

Try cleaning throttle bore and IAC valve and passageway?

Sniderd55
06-07-2012, 11:05 AM
Mostly when its hot but it has stalled after only a minute or two of driving.
Only stalls while coming to a stop.
It has restarted right away, but it also has taken awhile to start as well.
Acceleration is fine and no misfires.
There are no codes showing any problems.
And then I will have to consider your last two questions.

GTP Dad
06-07-2012, 05:42 PM
Have you changed the Crank Position Sensor! The symptoms are quite similar to a failing CPS.

Sniderd55
06-08-2012, 12:27 PM
Thanks for the input, and it does have some symptoms of that. But wouldn't the check engine light come on? Also, wouldn't there be codes in the computer showing a problem?

GTP Dad
06-09-2012, 08:20 AM
Not necessarily! There have been many members of this forum who have dealt with this stalling issue. The CPS usually will not set a code until it fails completely. A Grand AM owner had a car under warranty and they changed practically everything on her car for a stalling issue but didn't want to change the CPS. They were ready to contact GM Tech to come and work on the car. We advised her to insist on changing the CPS and once they did the issue went away. She didn't have any codes either!

Sniderd55
06-09-2012, 11:47 AM
Awesome, I really hope so. Also, do you think it could be a bad catalytic converter?

GTP Dad
06-09-2012, 05:27 PM
A bad cat would choke the engine even when it was cold due to the openings in the cat being clogged. However, you could drop the cat and see what happens. I still suspect the CPS.

Sniderd55
06-13-2012, 11:37 AM
Thank you it was the CPS!

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