Any sugggestions for GM problem???
 

I am having a heck of a time, along with my mechanic, in trying to fix my sisters 1991 Old Cutlass Sierra.

Do you all have any other forums I might call on?

For what it's worth, the car will not start. It had no spark so we changed the ignition module and the 3 coils that go along with it. 2 per each cylinder.

It started and ran fine for about a day, then back to square one. Checked for faulty grounding and found the harness that goes form the crank sensor to the module witha short in it. Changed the harness and the sensor. Nothing.

Changed the cpu and zilch. No trouble codes have appeared either.

My sister is driving me crazy using me as a taxi, but she's had it since new and want's to fix her up. Was running perfect, with 155,000 miles prior to this problem.

Suggestions? Ideas?

Thanks

Help........:(

What engine does it have??

I believe it's a 4.3 ltr 6 cyl. Not sure whether 4.0 or 4.3. It is a 6cyl though.

Does it have an el-cheapo aftermarket alarm with ign defeat?
How about the ign switch itself, Is it powering up the EFI computer as needed?
You may want to pick up a manual with wiring diagrams and
verify power to components like EFI ecu, coils, ign module, ect....
Just a couple of ideas now that the parts cannon is out of ammo.

Good luck and let us know.
Dr.D

Thanks. Will check the alarm as I do remember it having one............maybe.

If it does, make sure it isn't interuppting power to the ign system.
As most alarms are wired in-line to do this.
Dr.D

IWe happened to put it on the lift today after it drove around sluggishly for about 5 minutes.

I stand 6'3" and accidentally bumped my head to the rear of the catalytic convertor and it was slightly warm, not scalding hot, like the front of the exhaust pipe. ANyway, we removed it and lo and behold, it was clogged. Big time.

Replaced it with a straight pipe and changed the plugs. As of now, it is running pretty well, although the idle is a little low and it is stalling from time to time.

Will give it a nice hard ride tommorow.

The no-start condition can be caused by the "pick up coil" in the distributor. Cheap part, but the distributor has to come out and come apart to change it. The pick up coil is a weak link in GM distributors of that vintage. I replaced my entire distributor (91 Pontiac) with a MSD Pro Billet unit and the problem was completely solved.