1995 Other Chevrolet Models fuel injectors not sending fuel

Tiny
ARMYDOUG4
  • MEMBER
  • 1995 CHEVROLET
  • V8
  • 2WD
  • MANUAL
  • 12,500 MILES
I replaced my fuel pump and it works properly now but my engine will start when it is cold and runs for maybe 10-15 minutes then fuel stops coming from the injectors. When I try starting again I smell an electrical burning smell from passenger side engine compartment. I've heard ECM, fuel pump relay and more, what could it be?
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Wednesday, January 21st, 2009 AT 2:36 PM

5 Replies

Tiny
JDL
  • EXPERT
I need more info, can you give us the model, and litre size of your engine?

What type fuel system do you have, mfi, sfi, tbi, spider system?
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Wednesday, January 21st, 2009 AT 2:48 PM
Tiny
ARMYDOUG4
  • MEMBER
I have a 1995 Chevy 1500 2WD ext cab with 5.7L 350 and it has a TBI. I also have a manual transmission if that helps any. Thanks.
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Wednesday, January 21st, 2009 AT 3:19 PM
Tiny
JDL
  • EXPERT
You need to find the electrical problem. Look for melted or burnt wires. The fuel pump and injectors get voltage from the fuel pump relay. You can check those circuits. You have to start somewhere.

I believe the pcm is under the dash, passenger side, but the wiring harness goes through the firewall, check there also.
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Thursday, January 22nd, 2009 AT 7:48 AM
Tiny
ARMYDOUG4
  • MEMBER
Thanks, my model has both an ECM and PCM. The ECM sends the signal to the fuse pump relay. In the times when it won't start the fuel pump still gets energized which means that the ECM is still sending the signal to the fuel pump relay. I have to try and locate my ECM and check for burning or charring. Something is overheating and causing the fuel supply to get shut off.
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Thursday, January 22nd, 2009 AT 11:07 AM
Tiny
JDL
  • EXPERT
That's interesting, I don't think I've ever heard of a pcm and ecm on the same vehicle? I looked through two different databases, I didn't see it.

Sometimes the data bases use ecm and pcm interchangeably, I do it too. Usually, they use the term pcm when the computer controls both the engine and transmission. They use ecm when the computer only controls the engine. I couldn't find any info that showed your manual tranny is computer controlled.

As far as the fuel pressure, there will be an initial prime, where the relay is energized for a few seconds. If you have a hot fuel module, it may prime longer than normal. After that, if there is no rpm signal, the pump relay won't energize. Now, if there is an o/p switch in the fuel pump circuit, forget the relay, once you crank it enough to build oil pressure and that switch closes, the pump will run, there will be fuel pressure with or without an rpm signal. I don't believe the injectors will pulse without that signal. Some systems have the o/p switch, some don't.

The second database I looked at, showed the injectors get B+ from a different fuse than the pump.

I'm not sure it is safe to turn the key on, till you find the problem circuit. It's interesting.
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Thursday, January 22nd, 2009 AT 12:45 PM

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