Intermittent stalling

[antibotics]

First, I apologizing for not posting something related to grand prix. But my 2000 buick regal LS is essentially the same to grand prix with N/A 3800 II. Also I think this board has more activities, so I may get some response much faster.

Alright, I recently replaced the LIM gasket on my car. After that, car seems runs fine, smooth idle and runs great. But after the car is warm up, sporadically, the car will shut down when coming to a stop. No erratic behavior of Tach before stalling and the electric power is still on as I noticed the dashboard is still on. The car can be restarted immediately. So I think it is not likely crank position sensor. I checked all the connections that need be disconnected during LIM repair, all seem tight. The idle is smooth and car runs great before shutting down. So I think IAC valve and MAF sensor should not be the cause. I am really lost at this point. By the way, not service engine soon light, so no code to help the diagnosis.
Any suggestions are greatly appreicated.

[GTP Dad]

Welcome to AF!!

Try unplugging the MAF sensor and starting the vehicle. If the MAF is bad it shouldn't stall again however, the CPS will cause intermittent stalling so don't discount that either. Most of the time the CPS will not set a code until it totally fails and the car will not start. I suspect the CPS is your culprit but the MAF sensor is easier to try.

[antibiotics]

Originally Posted by GTP Dad

Welcome to AF!!

Try unplugging the MAF sensor and starting the vehicle. If the MAF is bad it shouldn't stall again however, the CPS will cause intermittent stalling so don't discount that either. Most of the time the CPS will not set a code until it totally fails and the car will not start. I suspect the CPS is your culprit but the MAF sensor is easier to try.

I cleaned MAF and it is not likely the problem. I brough the car into the shop and the mechanics found out the ignition switch is bad, "Ignition switch BTSI circuit is open circuited" Does this make any sense?

Update, more symptoms developed this morning, after I started the car (car will start fine), if I release the parking braking, the engine will quit. I end up releasing the parking brake before starting the car. I repeat this problem several times, engine always quits upon releasing of parking brake. Sometimes the gauges on the dash also act funny. Does this suggest the ignition switch is the real culprit?

[GTP Dad]

It sounds like you have a low voltage condition. When the e brake is set the drl's don't come on. When you release the brake the drl's come back on and would or may cause a voltage drop that is serious enough to cause the car to stall. This could also cause the gauges to act funny. Check and clean the battery terminals and check the connections to the starter and the block. Otherwise the ignition switch can cause issues that would cause the car to stall.