No fuel from the injectors

Tiny
DONNIE7
  • 1996 GMC JIMMY
  • 250,000 MILES

96 GMC 4.3l Jimmy fuel injection issue, no fuel from the injectors, tested power to each injector. Have power to each 4 strobe, 2 have constant power with ignition on but strobe when motor turns over.

i have replaced all the fuel system up to the fuel meter body, good fuel pressure the injectors have power to each. New pressure sensor, crank sensor I have done complete tune up. Dont understand why two of the injectors have constant power with ignition on but strobes when you crank it over. Before I did the work on it. Would run but after a few min hot or cold it would stall but if you feathered the pedal you could keep it running. When going down the road it would stall when you stopped suddenly or at a light. When it stalled in idle (hot)it took a cool down period before it would start again. I replaced fuel tank, pump, filter and relay. Now it wont even try to start plenty of fire air and fuel to the fuel meter body. Wtf im stumped. Need more than one thing to test. Unless I have one option. Please help.

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Friday, May 4th, 2012 AT 1:59 AM

9 Replies

Tiny
ASEMASTER6371
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Any codes? What is the exact fuel pressure? There is 1 12 volt feed to all injectors and the return to the pcm is toggled.

Roy

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Friday, May 4th, 2012 AT 2:02 AM
Tiny
DONNIE7
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I did not get any number codes just flashing CAT o2s EGR HTR and EVA can't get a running fuel pressure. Before it was 2 psi running so I replaced the pump tank and filter, what will cause two injectors to have a constant power whe ignition is on

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Friday, May 4th, 2012 AT 3:57 AM
Tiny
MIKEDEROUIN88
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Might have a bad computer, where did u get the crank sensor? And what was the fuel Pressure after u changed the pump?

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Friday, May 4th, 2012 AT 4:26 AM
Tiny
DONNIE7
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The sensor is a BWD. With power pulsing at each injector is right what else is controling fuel flow. I'm testing the fuel pressure in the morning. That pressure should be 43 - 56 psi not running, running it should drop to 3-10 psi is that correct

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Friday, May 4th, 2012 AT 5:08 AM
Tiny
DONNIE7
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Just asking how would the crank shaft cut off fuel completly? And can you tell me what the letter codes mean that I got

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Friday, May 4th, 2012 AT 5:32 AM
Tiny
ASEMASTER6371
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Pressure should be 55-62 minimum.

What side of the injectors are you measuring? There should be 12 volts all the time to the injectors. The return to the computer are what is toggled.

Flashing check engine light is a missfire code. You did not list this in your findings.

Roy

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Friday, May 4th, 2012 AT 10:20 AM
Tiny
DONNIE7
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The check ingine light is solid not flashing and I'm testing the conection at the top of the meter body going one by one with test light cranking it over for each.

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Friday, May 4th, 2012 AT 1:28 PM
Tiny
DONNIE7
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Also this the CSEFI so I'm testing at the electrical conection I have not removed the plenum yet but like I said with test light I get strobes to all injector should it show a constant light for all when ignition is on.

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Friday, May 4th, 2012 AT 1:53 PM
Tiny
ASEMASTER6371
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No, it should be toggled by the computer according to load.

Roy

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Saturday, May 5th, 2012 AT 1:58 AM

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