Car goes completely dead.

[JCByte]

I am in desperate need of assistance. My mothers corsica stalled out on her way to work, and I cannot find what is causing the problem. The car will be running fine for about five or so miles, doesn't seem to matter how hard or easy the going, and then just stalls out. Fuel pressure checks out, no engine codes, but no spark whatsoever getting to the spark plugs. If the car is left alone for a long period, it starts back up and runs fine for another short period and stalls out again. I even did this in idle (as a test) in the garage, and after about three to five minutes (or five miles driving), the car quit again!!! I tore apart the ignition module and coils, and all have checked good. I can only figure that something is heating up somewhere in the circuitry and causing a system failure, but where? I waited before the last stallout in the garage to see if I could cause the failure myself by tapping the ecm box, wiggling wires and making vibration tests throughout the important areas, but no luck. It stalled out like clockwork, about a minute later. the only thing I can find that is acting strange is rattling noise from the alternator, but I can't see how this would be the cause of a dead spark situation. I also tried to reset the ecm and all that stuff too. Anyone have any ideas?

[GMMerlin]

What year? Engine size? When this occurs do you have injector pulse?

If it is a no spark condition under a heat condition, I would look towards a faulty ignition module or a crank sensor.

[JCByte]

Sorry about lack of details.

1989, Corsica 2.8L V-6.

I don't know anything about the injector pulse because the first thing I noticed was the "no spark" condition. I have to admit, I'm not even 100% sure that it is heat related, but the explanation fits given the duration of time before stalling out. What do I do to check injector pulse?

Thanks.

[GMMerlin]

OK here are some ideas.
ECM....tap test it while the engine is running....if the engine reacts(stumbles,stalls,etc...), the ciciut board in the ECM is bad.

Use a test light to check injector pulse, remove one of the injector connectors and probe both wires (at the same time) while spinning the engine over. Does the test light blink? If it does but you have no spark, I would say the module is the problem.

Check the resistance of the crank sensor at the module connector...should be 900-1200 ohms.

[JCByte]

I tested the ignition module at a local parts store with their module tester for about 10 minutes ( about 30-50 tests) so it would get near operating temp to see if it would fail, and it kept passing the test. Perhaps I need to make it hotter to simulate the tempurature of the block area where it sits. I just don't know. This is getting good, right? *sigh*
Anyway, I just happened to be checking the Haynes manual for circuit directions and wondered the same thing about the crank sensor. I'll have to get back to you all on that after I check it too. The Haynes manual doesn't do a very good job discussing the electronic engine components.

Thanks for the specs on that Crank Sensor, and all your help so far GMMerlin! I am determined to find out what this thing is doing to make the car go dead.

[JCByte]

CRANK SENSOR READING IS OPEN. I STARTED THE CAR AND I RAN THROUGH THE USUAL TAPPING, PULLING, PRODDING, ETC., AND SHUT IT DOWN BECAUSE THE FAN IS REMOVED AND I DON'T WANT TO OVERHEAT THE ENGINE. I DIDN'T GET ANY CLEAR RESULTS UNTIL JUST NOW. WAITED A LITTLE WHILE FOR IT TO COOL AND CHECKED RESISTANCE AT THE CRANK SENSOR PLUG AND .... BINGO! PLUGGED IT BACK IN AND THE CAR IS DEAD FROM HAVING WARMED UP EARLIER. WHO WOULD HAVE GUESSED? AND NO ENGINE CODE EITHER??? OH WELL. THIS HAS BEEN A LEARNING EXPERIENCE TO SAY THE LEAST.

THANX AGAIN GMMERLIN.

I'll have to remember this and take note for future symptoms.

[GMMerlin]

Be carefull removing the crank sensor. Its plastic and will swell over time making removal difficult.
If it breaks off in the block you may have to remove the oil pan to get it out.....voice of experiance.

[JCByte]

My car (Baretta) has the same motor as this one, but with a five speed, there sure is more room for working!
They sure take up a lot more room with those automatic trannys. Anyway, aside from the "tight squeeze" between the oil and tranny pans, everything went smooth and the car is now running great.

Thanx again