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Ted G.
Ted G., ASE Certified Technician
Category: Chevy
Satisfied Customers: 6089
Experience:  20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
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1998 chevy truck 5.7 wont start. I hear the fuel pump running.

Resolved Question:

1998 chevy truck 5.7 won't start. I hear the fuel pump running. Runs when gas is poured into tb. replaced fuel pump 4 months ago for same problem, ran fine until now. Haven't checked pressure. What should it be 12-15 or above 55 psi. I've read conflicting answers.
Submitted: 5 years ago.
Category: Chevy
Expert:  Ted G. replied 5 years ago.
It should be 60-66 PSI at all times.
Customer: replied 5 years ago.
Any suggestions on what might be the cause?
Expert:  Ted G. replied 5 years ago.
Well if you do have good fuel pressure then I would look at the injector assembly. Normally the whole thing will not fail at the same time but You may have a loose connection or bad power feed.

Here is the digram of how they are fed from the ECM.

graphic
Customer: replied 5 years ago.
Replaced fuel relay, checked fuel press, less than 5 psi. I hear the pump come on, run 4-5 sec then stop. Can the pump run and not produce pressure? Remember it runs as long as I pour gas in the tb and I replaced the filter today. I sure hate to drop that tank again. 3rd time in 14 months.
Expert:  Ted G. replied 5 years ago.
Before you pull the tank make sure you have a good solid 12 volts at the pump connector and that there is no corrosion in there. It could have a bad fuel pressure regulator but I honestly have never seen one fail that badly, normally if they stick wide open you should see a drop of 20 psi or so, and they run poorly.
Customer: replied 5 years ago.
dropping the tank this afternoon, will let you know the outcome.
Expert:  Ted G. replied 5 years ago.
Okay.
Customer: replied 5 years ago.

Replaced the pump, works fine.

Final question, Why do I hear the pump run for the 3-5 seconds when the key is turned on but it doesn't produce enough pressure to start?

I ask because this is the 3rd pump in apprx 14 months.

Expert:  Ted G. replied 5 years ago.
So you replaced the pump and now it develops pressure and starts? The prime you hear is supposed to bring the pressure up to spec. If the new (3rd ) pump fixed it then I need you to check voltage when the pump is running, you may have a bad connection causing low voltage and that will burn up pumps.
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