1993 Chevy Caprice no start

1993 CHEVROLET CAPRICE
146,000 MILES • V8 • 2WD • AUTOMATIC
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REBEL300
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car will cut off after it runs for about 10 min it has good fuel pressure but when it cuts off there is no spark,coil icm,and dist have been replaced.could the pcm be the problem.
Dec 20, 2008 at 8:24 PM
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BUDDYCRAIGG
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you said you replaced the ignition control module.
but you're describing just that.

did you put the heat transfer grease on it?
Dec 21, 2008 at 2:19 AM
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REBEL300
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yes we put grease on it.
Dec 21, 2008 at 11:22 AM
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BUDDYCRAIGG
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there isn't too much to your ignition system.

you replaced the distributor, so it has a new pick up coil
you replaced the ignition module and coil.

the ECM could be bad, but that's pretty rare

i would check to see if the injector is firing the next time it happens.
if it is sparing, then the ECM is getting distributor reference. and you'll know the pick up coil is working and the ignition module is at least part way working.
Dec 21, 2008 at 5:57 PM
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REBEL300
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have no problem with the injectors are fuel the problem is when it shuts off you loose all fire from the coil and when it cools for about an hour then the coils start firing again somthing is killing the fire not the fuel
Dec 22, 2008 at 4:08 AM
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BUDDYCRAIGG
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i understand that you do not have spark.
i understand you have fuel pressure.

i want to verify that the ECM knows the engine is turning.
that's why i asked you to see if the injector is spraying.
Dec 22, 2008 at 9:52 AM
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REBEL300
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yes we have injector pulse
Dec 23, 2008 at 9:00 AM
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BUDDYCRAIGG
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I've asked 3 other moderators to look at this thread.

I just have a gut feeling that it's an ICM problem.
Dec 24, 2008 at 12:01 AM
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DOCHAGERTY
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If I may offer my humble opinion. I had a General Motors car doing the same thing, I tracked it down to a fuel injector or injectors heating up and shorting out. If the spark goes away it might be related to the PCM seeing a shorted injector and shutting the system down. I hope this is some data you can use.
Dec 24, 2008 at 10:38 AM
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RASMATAZ
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Recheck the coil and ICM-Dunno if this has a CPS if it does check it-
Dec 24, 2008 at 1:31 PM
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BUDDYCRAIGG
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Was the car having this problem all along and that's why you replaced the coil, ignition control module, and the distributor?

Was there ever a change when you replaced any of the parts?

I think I've got a way that we can test the coil.
If you have a remote tachometer (most $5 dollar dwell meters have a tach setting on them)
Connect the tach to the white wire going from the ICM to the coil. Set the meter to the low RPM range.
If you get a reading while cranking the engine, then you know the ECM and the module are working and the coil is bad.

If you don't get a reading then the problem is up stream, possibly the ECM or module.

I think I've got a way to test the module.
When is dies.
Put the electronic SparK Timing into by-pass mode.
Unplug the "set-timing" connector it's a single wire in the wiring harness on the left side of the engine, near the AIR control valve. tan with a black stripe.
If the car start up, the module is working. (or at least most of it)
So the problem would have to be upstream, possibly the ECM.

That's all the info I can come up with.

good luck
Dec 24, 2008 at 11:00 PM
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REBEL300
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yes this car has had same problem before any parts were changed.i have ordered a pcm and going to try that car has a short somewhere the dash lights and speedometer goes crazy when you try to restart after it cuts off.maybe it will fix the problem.
Dec 26, 2008 at 1:06 PM
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BUDDYCRAIGG
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good luck
let us know how it goes.
Dec 26, 2008 at 4:29 PM
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