mellowout

Greetings all, I hate to make another thread on this, but im giving it one last shot before i take it to my mechanic. car is a 93 LT1 M6

The symptoms:

• No start, starter turns
• electrics inside of car works
• no spark
• smelled it flooding while cranking
• service ASR, security, SYS, CEL (possibly unrelated)
• wont let me rev over 3k RPM (when it cranks, sometimes kicks into limp home mode, accompanied only by the service ASR, security, SYS, CEL)
• DTC 41 in bank 1 DTC 72 in bank 9
• ICM tested fine at autozone

I was able to charge the battery and drive it a couple of days before it died on me again previously, by the grace of God i made it home somehow. The ECM has been rebuilt about 2 weeks ago.

hooked073

why did you have to charge the battery?

THE 383 admiral

wont let me rev over 3k RPM (when it cranks, sometimes kicks into limp home mode, accompanied only by the service ASR, security, SYS, CEL)

sounds like this is your problem... there is a connection or PCM issue

mellowout

Had just got my ecm back and I was suspecting it was low

As for the pcm, my buddy just had a similar problem, fans cut on while the car is in run also. I'll have to take a look at the pcm

mellowout

Pcm = ecm? If so I just had it rebuilt

jaa1992

Check the wires and connectors to the ICM and Opti.
Shoot check all those connections.
Got a spare ICM and coil? Try them. The ICM can test good at those parts stores and really be bad.

mellowout

Tested the coil today, had good spark, ohmed it out and it checked out fine. tested for spark at the plug and it was very faint. Tried using some starting fluid to no avail. it didnt even try.

The weak spark could be due to my battery being low, its being charged right now, i will report back later with any results.

jaa1992- what gets me is that the car wont crank when its cold, its not as if the ICM is overheating. who knows!

jfb

Measure the plug wire resistance, they should be about 5000 ohms per foot. It may be time to replace the plug wires. Also, plug wire looms should all be intact and replaced if not and plug wires should be dressed so as not to touch metal.
When the starter motor won't crank the engine, can you hear the starter solenoid click? If so, you likely have worn contact in the starter that the solenoid forces together at the end of its stroke which switches 12v to the starter motor. If you can't hear the starter solenoid then you need to check the VATS which will not allow a crank if it does not see the correct pellet resistance in the ign key.

hooked073

K the way it sounded or the way I took it was you had to charge the battery to get it started.