stalling 95 lesabre
 

I have a 3800 in a 95 lesabre. New coils, fuel pump and sending unit. No codes but it does stall periodically. The ICM...where is it located so I can clean the contacts...also I see that the PCM fails on this so what is an indicator? Thanks in advance...

I'm not sure if this may relate, but during the stalling, do you notice any other electrical anomalies like with the door locks or power windows? Have a read here to see if this may apply to you.
https://www.gmforum.com/electrical-1...1999-a-303224/
...if not...then it may be your ignition control module. That is the thing that the 3 coil packs sit on. They tend to fail when it gets hot, but work fine when cold.

Try this test. With a cold engine, remove the 3 coil packs, and heat the ICM with a heat gun or hair dryer, reinstall the coil packs quickly and see if the engine will run.

The crank position sensor is another common heat sink problem.

When it stalls does it shut down like someone pulled a switch? Does it start right back up? Is it happening more frequently? These symptoms would point to a crank shaft position sensor, a very common failure.

My 1993 Buick Lesabre had that problem. It would sometimes stall at idle, or just before coming to a stop. It would always start up again first time with no problem.
I eventually diagnosed it to a single bad diode in one of the rectifier banks in the alternator. The spiky voltage was glitching the PCM and the engine stalled. Before I put in the new alternator, I used my electronics bench oscilloscope to view the alternator output. I could see the spikes. The new alternator completely fixed the problem.

But not a common failure on the 3800. The CPS, on the other hand, is an extremely common failure. I'm not saying the alternator is not the problem, but we need to focus on the likely before we get to the obscure.

CHECK YOUR EGR valve..... I had similair problem. Stalls when coming to a stop or idling. I changed out TPS, CPS, CKPS, IAC, O2, TPS, MAF and it still stalled. I finally found a thread with a lady who car had similar problems and it was her EGR valve. I checked mine by doing the test as stated here in the troubleshooting and test section. It was working but the internal valve was bad. I went to the junkyard and I bought one for $8 and I was finally rid of the stalling issue. Try to clean it first and run it for a few days if you get a stall again try a new/used one.

I guess the question we should be asking is does the car stall at idle, or does it shut down when driving?

Car did have a new gm EGR added. Kids car and he has told me it only stalls in motion (never in the driveway). I will go forward and have him clean the contacts on the ICM...and PCM. Then replace the CPS....then the ICM if the issue persists. I see that the PCM seems to crash often on 95's....is this true? Thanks for the directions...

Bristang

seems to be the most complains of pcm failure is 95