My truck cranks normally but won't start?

2001 CHEVROLET SILVERADO
200,000 MILES • 6.0L • V8 • 4WD • AUTOMATIC
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OUTLAWSGHOST
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My truck cranks normally but won't start. It will on ether but shuts off. I've replaced fuel pump and filter, plugs wires, cam shaft sensor ,and crank sensor. Good fuel pressure to fuel rails. coils and injectors are good. It's got spark. Fuses and relays are all good. Also replaced battery. Alternator and starter are good. Nobody can seem to figure it out. Please help.
Nov 29, 2020 at 3:55 PM
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ASEMASTER6371
  • ✓Experienced Mechanic
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Good morning,

Did you verify power to the fuel pump while cranking and when you first turn the key to on?

I attached a diagram of the relay and the pump for you. You need to verify power to the relay first on pin 30.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

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

Then 85 gets power directly from the ECM.

The grey wire at the pump is what needs power.

Roy

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Jan 25, 2021 at 2:16 AM
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OUTLAWSGHOST
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Hi Roy, I had my neighbor check it out and the pump and relay are indeed getting power.
Jan 25, 2021 at 2:16 AM
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OUTLAWSGHOST
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I have also changed the MAF sensor when I replaced all the rest of those parts.
Jan 25, 2021 at 2:16 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
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If the pump is getting power and not running, then you either have a bad pump or ground.

Did you verify no fuel pressure?

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Roy
Jan 25, 2021 at 2:16 AM
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OUTLAWSGHOST
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Fuel injected is getting power and running. I checked the fuel pressure at fuel rails and each time it's between 50 and 60.
Jan 25, 2021 at 2:16 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
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Okay, next you will need a noid lid light to attach to one injector and crank the engine. It should flash indicating the ECM is commanding the injector open to flow fuel.

You can rent one at a parts store for this test.

Roy
Jan 25, 2021 at 2:16 AM
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OUTLAWSGHOST
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Okay, I'll try that next. Thank you.
Jan 25, 2021 at 2:16 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
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You are welcome.

Roy
Jan 25, 2021 at 2:16 AM
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