1992 GMC C1500 1992 GMC WILL NOT START, NO SPARK

1992 GMC C1500
180,000 MILES • V8 • 2WD • AUTOMATIC
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VETTE68
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I was driving along then motor quit, NO SPARK, all ignition components check out fine, power at all the right places, I pulled the ECM connector off the ignition module and jumped terminal A to C and got healthy spark but no gas spray from the injectors, pored some gas down the throttle body and she runs for a few seconds, got late so I put every thing back the way it should be and turned the key one last time and she fired up as normal, went for a run, every thing seemed fine, next morning NO SPARK again, could it be the ECM or the ESC/EST ?
Please Help.
Dec 1, 2009 at 10:17 AM
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JDL
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  • 16,098 POSTS
Welcome to the forum, my info showed est. During cranking, the ignition module controls the spark, uses signal from pick-up coil. Check primary circuits at coil when problem occurs. Pink wire is voltage. Should be a pulse on the white wire, engine cranking. Any trouble codes?
Dec 1, 2009 at 10:46 AM
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VETTE68
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engine service light NOT on, NO service codes, just the code 12 diagnostic code.
So if I put a test light on the white wire it should flicker during cranking ?
Dec 1, 2009 at 1:09 PM
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JDL
  • CAR REPAIR CONTRIBUTOR
  • 16,098 POSTS
Yes, it should. If the lite is on and doesn't pulse, I'd check the pickup coil and ignition module.
Dec 1, 2009 at 2:45 PM
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