Thread: Engine stall while driving

Originally Posted by Scottydoggs

crank sensor never sets the code for it. if its just random stalling, id start with a crank sensor.

Thanks! I appreciate your insights. While you replied, I edited my post and that's my suspicion although I don't know enough about crank sensor. Would struggle to start when warm be a symptom for a bad crank sensor?

And it always restart fine after the engine stall and runs/idles rough. Can a car idling rough with a bad crank sensor?

Originally Posted by Scottydoggs

what year and engine you got there? could be a bad fpr. and maybe the crank sensor together.

Sorry I did not include the model and year. I will edit the original post.

It is a 2005 Pontiac Grand Prix base model. Engine is the 3800 series 3 natural aspiration.

Originally Posted by Scottydoggs

not the fpr then. back to a crank sensor.

cat could be clogged up too, them na engines love to clog the cat. but that would come with the car feeling like its lost a lot of power. and the cel would flash when you floor it.

Thanks! It seems the crank sensor could be the cause.

I haven't floored it but I did not feel any lose of power. No check engine light either. It drives totally fine and then just suddenly stalled. The cat was replaced with a OEM one four years ago and I only drove less than 25000 miles on it. I hope GM's cat is not that bad......

Originally Posted by Scottydoggs

check the crank sensor harness for damage while doing the gob, they tend to get old and brittle and get cracks in the insulation, then it fails.

Thanks a lot for the insights. I will check that for sure. I also used the AC for the first time in a while but I don't know whether this is related to the engine stall problem.

I took the car to the shop and they told me that it is a faulty ignition coil. It is puzzling to me that a ignition problem did not set the check engine light. I guess I have never let the car run for a long time after it died so the engine light does not have enough time to show up. But I will try to talk to the mechanic to see how he did the diagnostic. I will report back what I found in more details.

I had an ICM fail on my 00 GT this exact way. Just slowly came to a stop with no amount of engine response from the pedal. Then when it would start it ran like crap. I also found a cracked coil at the same time. Swapped ICM and coil and it fired right up like nothing happened.

Originally Posted by FordMan77

I had an ICM fail on my 00 GT this exact way. Just slowly came to a stop with no amount of engine response from the pedal. Then when it would start it ran like crap. I also found a cracked coil at the same time. Swapped ICM and coil and it fired right up like nothing happened.

Exactly. Eventually I have to replace the ignition control module and one ignition coil. The car runs fine after that. The only left problem is that the misfire destroyed the catalytic converter so I have a P0420 code now. This is the second time in four years that the ICM failed and then the catalytic converter failed consequently. I love my 05 Grand Prix but I am more inclined to replace it with something newer and more reliable.

My 97 GTP is acting something like this. It seems to be heat related. It will start just fine, idle normal, and drive normal for anywhere from 2 to 15 minutes, then start chugging and eventually stall. With Torque OBD connected once it starts to stall the vacuum reading stays at 0.04, no boost or vacuum. I found the vacuum tee under the snout disconnected, but replacing it did not solve the problem. It has thrown me a code, P0121: Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem, so I replaced the TPS with another I had off another TB. Same issue. Harness seems OK, not rubbing on anything. Once it stalls, it wont start for anything, but if you wait approx 15 minutes starts right up like nothing is wrong. Could it be something as simple as ICM?

Could very well be. Might be getting heat soaked and then failing. Any ICM from a 3800 car should work if you have someone around that has one that you could "borrow" long enough to troubleshoot. If it is the ICM, then off to the junkyard you go.

I tend to agree with the crank sensor theory, only because I had a Jeep that did the same thing, stalling while driving then after it cooled down it started and ran again. I brought it into the shop multiple times but by the time it got to the shop the problem was gone, and they couldn't figure anything out. After exhaustive research online, I took it in and told them to replace the crank sensor. They called back an hour later and said they didn't think it was the crank sensor. I said, maybe you misunderstood, I told you to replace the damn sensor. They did and it ran happily ever after, at least until I sold it a few years later.