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1999 Chevy Silverado fuel pressure

Tiny
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  • MEMBER
  • 1999 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 154,000 MILES
My truch has a hard time starting if I try to start it right off the bat. But if I let the fuel pum build some pressure itll start, so I hooked up the pressure guage and turned the pump on and it went up to 15psi then down to zero, then I tuned the engine on and I ujusted the regulator to the correct psi. And when I turned the truck off it went back to zero psi. Is this a pump or a regulator problem?
-thanks to all
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Monday, April 6th, 2009 AT 12:34 PM

14 Replies

Tiny
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That fuel pressure is way too low. It should have been 60-66psi

If pressure drops quickly, the vehicle may have a leaky fuel line, a leaky fuel pump check valve, a leaky fuel pressure regulator or one or more leaky fuel injectors.
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Monday, April 6th, 2009 AT 12:48 PM
Tiny
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I can adjust the fuel regulator to 66 psi I'm just wondering what's causing it to drop to zero
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Monday, April 6th, 2009 AT 3:01 PM
Tiny
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One of the above will drop the fuel pressure
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Monday, April 6th, 2009 AT 4:18 PM
Tiny
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Is there anyway I can check them? I just recently(maybe 7-8 months ago) got a new pump. How do I fix an injector leak? New ones?
-thanks for your help
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-1
Monday, April 6th, 2009 AT 5:42 PM
Tiny
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Is there anyway I can check them? By doing a few pressure drop by activating it one at a time-your best is just replace it
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Monday, April 6th, 2009 AT 6:10 PM
Tiny
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What should I replace?
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Monday, April 6th, 2009 AT 9:33 PM
Tiny
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Honestly sir-I don't want you to throw parts at it till its fix-reading your 1st post I'll replace the fuel pump if it was me. The fuel pump should hold pressure for a period of time not just drop to zero as you stated.
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Tuesday, April 7th, 2009 AT 12:08 AM
Tiny
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Ok that's not a problem as the fuel pump is on a warranty, could it also be the regulator?
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Tuesday, April 7th, 2009 AT 12:11 AM
Tiny
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Yes sir could be the regulator if its ruptured and not maintaining the fuel pressure
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Tuesday, April 7th, 2009 AT 12:36 AM
Tiny
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Ok is there anyway I can test these to see which one it could be?
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Tuesday, April 7th, 2009 AT 12:38 AM
Tiny
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This what I want you to do-pinch off the return line hook up the fuel pressure gauge turn key on and monitor the pressure it should increase considerably over the specified fuel pressure specs.

Do you have a TBI or MPFI fuel system? At the pressure regulator do you have a vacuum hose connected to it. If so look inside if it has fuel if so the regulator is defective
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Tuesday, April 7th, 2009 AT 12:55 AM
Tiny
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Ok I will try that. And I'm not sure what system I have. Should I pinch the hose while it's running or with just the key on?
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Tuesday, April 7th, 2009 AT 12:58 AM
Tiny
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Do it while its running
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Tuesday, April 7th, 2009 AT 12:59 AM
Tiny
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Ok will do. I'll give you a word tomorrow
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Tuesday, April 7th, 2009 AT 1:01 AM

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