1991 LeSabre Stalling In Traffic

Greetings, I have a 1991 Buick LeSabre that I've owned for a few months. When I bought the car it was running very rough, I gave it a compression test and the engine is in good shape. After replacing the plugs and wires it ran better but still very rough. I put it in for repair at my local gas station and the owner/mechanic knew what it was right away, the coil pack and the ignition box. The car ran great and had no problems. After a couple of weeks I had to take an unusual route home due to heavy traffic and in following a friend who knew the route I had to accelerate more than usual (didn't floor it, maybe half way down) and the check engine light came on. Having had cars in the past that this light would come on from time to time with no consequences I didn't think much of it. Almost home free I was stopped at the last traffic light before reentering the highway close to home and the car stalled. After 4 or 5 attempts at restarting the car started and I was on my way. The car continued to stall at more and more frequent intervals and I managed to get it to my local gas station. In his trouble shooting the mechanic said that the computer was telling him that the cam speed sensor was bad, he replaced the exterior pick up half and the check engine light didn't go out, he went into the timing chain and the magnet half of the cam speed sensor had broken, he replaced that and everything seemed just fine. I have used the car for days including some 1 to over 2 hour trips with not a hint of a problem. Last night I was returning from an event and about an hour or more into the return trip I hit heavy stop and go traffic, after a half an hour of this the car stalled. I restarted the car and it continued to stall every few minutes in traffic. I left the traffic clogged road and took a different route and the car ran fine. Has anybody experienced a similar problem with this model? The problem now is that it has the stalling problem in traffic without the check engine light coming on so my mechanic says that if the light doesn't come on the computer can't tell him what the problem is and if he can't replicate the failure it will be very hard to find. I have searched the posts in this forum and can't find this exact problem that I have now. I was a professional dealership motorcycle mechanic for 16 years and am a life long hot rodder so I'm use to working on my own cars but I'm afraid with all the newer computer controlled systems on board I'm a little lost. Thank you in advance.

Does it stall when you are stopped/idling in gear? If that is the case, put it into neutral when idling when it starts to do it again. If that prevents it from stalling again, I would be looking to be sure that the Idle Air Control valve is properly functioning. Also check the vacumn lines for leaks.

Another thing that would be good to do is put fuel injector cleaner in the gas tank on the next fill up.

Thank for the reply, no it doen't seem to be only in gear and at idle when the problem occurs, a couple of times I was underway at reasonable low speed (lets say under 25 MPH but I'm not certain) and it just shut off. A couple of other times the engine had not yet quit but I could tell something was wrong and depressing the gas pedal didn't provide accelleration but nothing and then in short order it shut off. The car won't restart immediately but it takes a few to several attempts to restart, then its fine for a little while and then it shuts off again.

Its beginning to sound like the crank sensor. See other posts about stalling or dieing.

Thanks rustbucket, I will recheck all the stalling posts. Gotta love this forum. I used the Buick today for work, 36 miles one way and there and back no problem at all. Just a quick question before I search the forum again, would not a malfunctioning crank sensor turn on the check engine light? Haven't seen that light since the cam sensor was repaced.

Probably not. The computer must think the engine is not turning and shuts off the fuel. On my '87, it was stalling and never had a light. There was a recall on it after a couple of years, and they replaced the crank sensor.

Thanks, I just called the the mechanic and I'll drop it off tonight for a crank sensor. Lets see what happens. I really appreciate the help.

Went to autozone today with similar problems. My 97 started running rough, stalling especially at low speed. My check engine light was going on and off for some time but then started flashing. He put on a scanner and seems to think its the throttle position sensor. Hope it works when I get it put in. Good luck!