1994 Buick LeSabre Limited...

First off I would like to say hello... Now to the car :banghead:

Ok here's the deal, my dad bought me this car so I could get from point A to point B and the first day or two was great. Then around day 3 or 4 it started this problem that has been going on for about 4 months now and it is becoming a serious safty hazard for me and anyone that rides with me. I have read that some other people are having this same problem that I am getting ready to explain but I could not really find a good awnser.

The problem... The infamous random stall, here's the picture, let's say I am driving either downtown or out on the highway all of a sudden out of the blue the engine cuts off. I lose all powersteering and the ability to break after the break pedal has been pushed once (this problem also happens sitting at red lights etc.). Well I will pull over if I can and have the car come to a complete stop and I have to put it into park before attempting to restart it. I know I need a new starter and possibly an alternator but thats besides the point. Once I get the car started again it will usually run ok for a while and then again who knows. Below I have listed the parts/repairs we have made to the car so far.

Parts/Repairs
1) Cranksaft Sensor (Firestone)
2) MAF Sensor (Me)
3) Ignition Coils (Me)
4) PCV Valve (Me)
5) Fuel Filter (Me)
All parts were new.

Car Specs
1994 Buick LeSabre Limited
3.8L V6

Well that's my story and I am hoping to god that someone can help me with this problem. Thanks in advance. :)

Basically the same problem this guy is having but I have already replaced the crankshaft sensor. :banghead:

http://www.automotivehelper.com/topic217926.htm

When it dies you need to confirm spark, injector pulse and fuel pressure to find this.

Divide and conquer.. the 3 areas ...Spark, Fuel source, Fuel inject.

**The vehicle powertrain electronics need a good stable power source such as an alternator and solid battery connections, information connections and grounds.

* As far as troubleshooting you need assistance. Somebody or a test aid.
What I mean is trobleshooting needs either someone to crank while you quickly test for spark or some test setup to inform you while your cranking the disfunctional engine whats not working.
* Find a situation that can repeat the problem safely.. such as running the car in the driveway being sure it doesnt overheat. Driving on low traffic road with an accompaning vehicle or cell phone.

I believe its not the Security VATS system because it is designed to allow for safe driving by not disabling while driving.. It turns off fuel pulses.

It could be your IM (Ignition Module)... or associated wiring all the way back to the PCM. Symptom ::Drastic cut of power.
Find a junker IM or even a PCM and swap the chip.. (easy swap)

* Fuel Pump.. When it stalls go and press the Shrader valve on the fuel rail and expect a good spray or if it dribbles you lost fuel pressure.. (35psi).
but often irractic power and no start and more various symptoms like chugging before it stopps.

* Fuel Pulses.. Controlled by the PCM. (I think) disconnect the Camshaft sensor and see if the car runs or doesnt stall. (GM advice) (easy swap.. $20) It could be failing while the PCM is using it.

Some Ideas.. here.. hope it helps.

Thanks guys I will try some of these suggestions.

When I had the exact same problem on my 92, it turned out to be the Ignition Control Module (about a $200 part). Find one in a junk yard, especially a pull it yourself junkyard. Try that, and if that does not work, then consider the new computer, and test the fuel pressure, etc. like has been suggested.

When I had the exact same problem on my 92, it turned out to be the Ignition Control Module (about a $200 part). Find one in a junk yard, especially a pull it yourself junkyard. Try that, and if that does not work, then consider the new computer, and test the fuel pressure, etc. like has been suggested.

I am planning on getting a new ICM before the PCM just because it will be a super easy switch. ANd yes the fule pressure is fine which I had check by Firestone.

Well here is the status report, tonight I disconnected the CamShaft Sensor and drove it and I could not get the problem to happen again I even stopped and restarted the car 3 or 4 times and still could not get it to stall. I also did not notice a difference in performance or driveability. Once I got home I reconnected it and did the same drive again this time a little longer but I still could not reproduce the problem. Any ideas on this one? :banghead:

Next thing I am planning on replacing is either the ICM or ECM, which would you recommened I try first? :redface:

Well here is the status report, tonight I disconnected the CamShaft Sensor and drove it and I could not get the problem to happen again I even stopped and restarted the car 3 or 4 times and still could not get it to stall. I also did not notice a difference in performance or driveability. Once I got home I reconnected it and did the same drive again this time a little longer but I still could not reproduce the problem. Any ideas on this one? :banghead:

Next thing I am planning on replacing is either the ICM or ECM, which would you recommened I try first? :redface:

Unless you can get either at junkyard pull-it-yourself prices, don't get either without a professional diagnosis. You'll pay about $65-$75 to have it diagnosed, but $200 for an ICM or over $100 for a computer (neither of which you may need). Therefore, I would either get the parts super cheap (like $10-$20 each cheap) or get it properly diagnosed.

Whoa...wait a tick before you start throwing parts it it. First, have you had the diagnostic codes pulled? Autozone can do this for free.

Second, Autozone or similar can test the ICM for free.

Third, you can test the coils yourself (park in a dark garage/road, pull plug boots off each terminal with INSULATED pliars, if no or erratic spark then the coil is failing at operating temperature).

GREAT you found the problem.?.

You did say you can run fine without the camshaft sensor..
Thats the recommended Camshaft senor test in the GM book is to see if it runs well without it.

Put in a new Camshaft sensor...They are easy and about $20..

Update,
Running without the camshaft sensor finally made it stall. So today I went and had the ICM checked by Autozone and it checked out as being fine. So since I had it scanned by Firestone and they said it would either be the crankshaft senor, ICM, or ECM we bought a ECM for $100 (since we already did everything else) from Autozone and I have not had a problem since! Ran it about 20 miles and could not get it to even try to stall. It used to stall every 2 miles or so. Well keep your fingers crossed and thanks alot for the help guys you have been loads of help. Hopefully this will help someone else that is having a similar problem.

That happens.. most difficult when a bad part is replaced with a bad part.. Quite a pain.. Been there..

Good luck.

Well it has been 2 days about 150 miles or so and no problems. I guess now I can work on making the car look nice :)

Yep.. well feel like you have done a great job at a most difficult problem.

What you learned offsets the cost.. some.

Enjoy each mile with no problems.