Random stalling issue

[Iron]

Howdy Grand Prix forum goers,

About 2 months ago my car had a problem where it would randomly stall and then it would take a good minute before it would start up again. I took the car to my mechanic, and he did a general tune up, and he said nothing about anything that would cause stalling. The car stalled a few times shortly after this, but the problem disappeared until today. Today it stalled 3 separate times on the way to/from school (twice it started back up after about 5 seconds, the first time it took atleast 3 minutes to get going again).I tried to look for a pattern of when it would stall, but the only thing that SLIGHTLY correlates is cold weather (it was -35 C/-31 F here today), but that doesn't really make sense because it starts fine after it's been left sitting overnight, and then seems to stall after about 10 minutes of driving.

Anyone who could shed some light on possibilities before I take my car back to the mechanic would be appreciated.

[TimmyGTP02]

sounds similar to what my car did last winter. It would take longer than 3 minutes before it started again. My problem was my Mass Air Flow sensor. I unplugged it to make sure and it ran fine so i knew that was it. So if you haven't checked that out I would do that.

[grandprixgtx00]

I would have to say maybe a bad CPS (crank position sensor) Does your tach ever do weird things before stalling?

[Iron]

Originally Posted by grandprixgtx00

I would have to say maybe a bad CPS (crank position sensor) Does your tach ever do weird things before stalling?

Actually you might be right. It isn't a common thing but there have been atleast 3 occasions where my tach went right to zero even though the engine was still running (also the "TCS off" light came on"). Would this behaviour resemble a bad CPS?

If it's my mass airflow sensor I'm gonna shoot something because I replaced it last year lol.

[olopezm]

I dont't know about the CPS but accorfing to thw symptoms described by you and grandprixgtx00 that might be your problem.

Another possibility could be a fuel pump going bad. It does not necesarily has to stop working, it can be intermmitent and start working again after a few minutes. However you mention it had been working fine for the last months so that makes me think. Do you have access to a fuel pressure tester?

Best regards,

Oscar.

[grandprixgtx00]

Originally Posted by Iron

there have been atleast 3 occasions where my tach went right to zero even though the engine was still running (also the "TCS off" light came on"). Would this behaviour resemble a bad CPS?

This is classic symptoms of a bad CPS.

[Scrapper]

first i would check fuel pump psi..then if good i'd check maf and cps.

[richtazz]

I agree with grandprixgtx00, the tach dropping to zero and the trac-off light coming on are classic symptoms of a crankshaft position sensor going bad. Without those symptoms, the MAF would be my guess.

[Iron]

Thanks for all the replies mis amigos!

It turns out it was indeed the crank position sensor .

[sixpix]

I have been having the same random stalling with my son's 2002 Grand Prix. It's been going on for several months now (about 10 times in six months) and almost always starts back up. Just last night he mentioned that the tach drops to zero when this happens and sometimes the car keeps running. I had just read your posts the night before he mentioned it. Thanks for posting and hopefully this will solve my problem too. Thanks!

[Tech II]

There is stalling, and there is stalling.......by that, I mean, other symptoms can vary the diagnosis......

Let's say fuel pump......an intermittant fuel pump can cause a stall.....however, usually when this happens, the car will not restart, in some cases it may not restart for a long time.....in cases like this, where a fuel pump may be the culprit, keep a can of carb cleaner handy.....if car won't start, after a stall, spray some into the intake....if it starts and runs until the carb cleaner is used up, you know you have a fuel delivery problem....

Let's say, MAF......this can cause a stall, AND also a hard or no restart...if the vehicle won't restart, disconnect it and try to start it.......if it starts, shut off vehicle, reconnect, and try and start it.....if it doesn't start, it's the MAF....

Crank sensor.......more often than not, when it stalls, it won't restart right away....may take a few minutes.....sometimes, this also can be caused by a bad ICM......

Another possibility, is a dirty IAC pintle and throttle plate bore.....usually the car will restart, especially if you slightly step on the gas pedal.....

Another possibility is a leaking fuel pressure regulator....it can cause a stall, and hard restart on a warm engine.....sometimes when it starts, it's accompanied by black smoke from running rich....

These are just a few things that cause a stall....