No Pulse to injectors

Tiny
BBOYETT86
  • MEMBER
  • 1991 CHEVROLET SILVERADO
  • 197,000 MILES
Chevrolet k1500 getting spark to all plugs, gas to TBI, continuity from ECM to injectors, but no pulse to injectors. Please help! Every possible part I could test passed just wondering if it is an ECM problem?
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Wednesday, January 25th, 2012 AT 7:32 AM

7 Replies

Tiny
RIVERMIKERAT
  • MEMBER
Hello,

This sounds like you have an ignition module that has gone partially out. Here is the engine and ECM wiring diagrams so you can see how the system works. Use this guide to check the connections/signals.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know what you find.

Cheers
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Wednesday, January 25th, 2012 AT 7:59 AM
Tiny
BBOYETT86
  • MEMBER
Checked the fuel relays all good. So I replaced the ignition module and the truck fired right up, good call! I love this site, thanks again.
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Wednesday, January 25th, 2012 AT 8:47 PM
Tiny
RIVERMIKERAT
  • MEMBER
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
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Thursday, January 26th, 2012 AT 4:04 AM
Tiny
LARRAN EPPARD
  • MEMBER
  • 1990 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 65,000 MILES
I am working on a C 1500 pickup with a 5.7 engine. With a noid tester on the TBI lead I get no pulse. I have tried disconnecting all sensors and have even replaced ECM. I have voltage on one side of injectors, but the ECM will not provide ground. I have tested the ECM for power and ground as best I can and all seems good. Engine will start if you pour gas in throttle body but will only run until gas in intake is gone. New ECM did not come with prom chips not sure if this may be my problem. Also, not sure about leads from distributor is this where the ECM sees that the engine is turning? This model does not have a crank sensor and I cannot find a parts listing for a cam sensor. Any help would be greatly appreciated.
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Wednesday, September 5th, 2018 AT 10:40 AM (Merged)
Tiny
RASMATAZ
  • MEMBER
Try replacing the distributor magnetic pick-up coil and see what happens. Been here before with the pick-up coil that hooks up to the ECM-in the distributor-fire right up.
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Wednesday, September 5th, 2018 AT 10:40 AM (Merged)
Tiny
LARRAN EPPARD
  • MEMBER
Rasmataz,
Thanks for the reply. This was where I was going next but I was not sure if the ECM got a signal from the distributor. Pulled cap and found several problems in distributor. Replaced distributor and problem is solved. I can see now that the older engines got their reference from the ignition module. Is this still the way the ECM gets reference or is that the job of the crank sensor now?
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Wednesday, September 5th, 2018 AT 10:40 AM (Merged)
Tiny
RIVERMIKERAT
  • MEMBER
That depends on the car maker. Thanks for letting us know your issue is resolved.
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Wednesday, September 5th, 2018 AT 10:40 AM (Merged)

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