Intermittent stalling after LIM repair

[antibody]

Hi folks,

After 8 hour outside in 35 degree, I finally put in a new LIM gasket on my regal ls. However, my wife complained that I screwed the car since it stalled once on her. I checked the car over, no loose connection of power and vaccum, engine runs smoothly. Today, as temprature is extremely cold, I was able to reproduce the stalling twice. Here are some symptoms of the stall,
The stall happens when engine was still cold, the electric power is still on, the car can be restart easily.
Car runs fine before dying, no surge in the rpm or any difficulty in the power.
When car was dead, almost all lights are on, including service vehicle, ABS, trac off and sevice engine soon.
I noticed that service vehicle soon, ABS and trac off light are occasionaly illuminated, mostly when pulling the car out from the parking ramp.

So my guess is that it has nothing to do with the LIM repair. After some research, I guess the wheel speed sensor harness may go south, which is a common problem in many gm vehicles.

Any suggestions? Thanks.

[myfirstbonnie]

A wheel speed sensor would not cause the car to stall. Check the ground leads under the coils. Also check the connections to the CPS and ignition module and battery.

[Archon]

When it stalls, check to see if you are getting spark. Checking fuel pressure would help, too. Also, take the car somewhere to get the code pulled.

[antibody]

When it stalls, check to see if you are getting spark. Checking fuel pressure would help, too. Also, take the car somewhere to get the code pulled.

The light was only on for a short while. I tried to pull code using a OBD II scanner, but it seems there is no code stored.

Now assuming I did mess some electric connection, what is most likely to be affected during a LIM repair. I will check battery ground tonight as the spilled coolant may foul the connection.

[Archon]

Maybe you could take the scanner with you, and try to catch the code while the light is lit. Any connection that was moved, or disconnected during the repair would be suspect.

[antibody]

Folks,

Here are some of my finding, I don't know if they will cause my car to stall?

Bascially all electric connection seem tight and no exposed wire. But I did notice:
1. Some corrosion on the battery cable, possibly caused by the coolant spilled during my LIM repair as I didn't notice these things before.
2. The battery ground is covered by some debris, such as leafs and small piece of paper towel. I guess these gargage was dumped in there during LIM repair when flipping the coolant tank.
Does this sound right for the cause of stalling?

[00Beast]

Not really, but clean the connections and make sure they're tightened. The junk would only matter if you had it under the connection.

[antibody]

Still working on the intermittent stalling.

All wire connection are tight and battery terminal connection are cleaned.

But I stll have the stalling, now I found the stall always happen at low speed, often at stops, after the car is warm up. The idle is pretty smooth and stable, so I think I can rule out the IAC valve. I also didn't notice any erratic behavior of tach, so propably not the CKP. I wonder if the Engine Coolant Temperature sensor or its harness is giving me the issue?
Any suggestions for this low-speed stalling after warming up?

[antibody]

Ignition switch?

Ok, I brought the car into shop today. The shop is highly regarded in local community. The mechanics didn't find anything screwed during the LIM repair. He found the ignition switch is bad, " Ignition switch BTSI circuit is open circuited". Does this make sense?

[Archon]

That's the Brake Transmission Shift Interlock. It may keep you from being able to shift out of park, or into park and remove your key, but shouldn't cause a stalling problem.

[antibody]

That's the Brake Transmission Shift Interlock. It may keep you from being able to shift out of park, or into park and remove your key, but shouldn't cause a stalling problem.

Do you mean the faulty ignition switch will not cause a to stall? Or you mean this specific malfunction of Brake Transmission Shift Interlock will not cause my car to stall?

[Archon]

The latter.

[antibody]

The latter.

Thanks for the quick reply. I did got my key stcuk in the ignition cylinder several times before. So the ignition switch is indeed faulty. I wonder if this faulty switch would also cause some contact problem that shut down my car?

[Archon]

While that code may point to a faulty ignition switch, it could also indicate a problem in the wiring or the BTSI solenoid itself. I don't recall any occurrences of a faulty ignition switch causing a stalling problem with the Bonnevilles. I don't know about the Regals.

[00Beast]

I don't think it would cause stalling, it would cause non-starting like what happened to Black Pearl's car at the 2009 October MN meet.

[antibody]

Ok, some update, more symptoms emerging 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?

[Archon]

I can think of no cause that would have the car stall when releasing the parking brake. Does the car start right up? Had the CEL ever come back on? Have you checked for spark if it doesn't start right up?

[Billha]

I haven't seen any updates on this post. Did you ever find the cause of the stalling problem?