1999 Chevy Silverado

Tiny
SNOBRDRPRO
  • MEMBER
  • 1999 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 15,400 MILES
Sometimes, more in the morning when its cold my truck wont start if I crank on it right away. I have to let the fuel get pressure and it'll start up and sometimes it wont start and then the 2nd time I crank it it fires right up. Iv changed the fuel pump, filter, cleaned injectors, changed fuel pressure regulator. Dont know what it could be now?
Monday, March 30th, 2009 AT 4:36 PM

20 Replies

Tiny
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Whats the fuel pressure when you turn the key on with the engine cold?

How cold are we talking?
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Monday, March 30th, 2009 AT 7:39 PM
Tiny
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I don't have a pressure guage as of yet, but I live in Carson city, Nevada so mornings are 20's and 30's
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Monday, March 30th, 2009 AT 9:09 PM
Tiny
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Gonna have to have one to see if the pump is priming when cold or not. That way we can see if its pump or electrical or what.
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Monday, March 30th, 2009 AT 9:27 PM
Tiny
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Ok it is a pretty new pump, could it possibly be a bad gasket somewhere?
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Monday, March 30th, 2009 AT 9:39 PM
Tiny
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I wouldnt suspect gasket.

Could be a bad relay for the pump. Does pump turn on when vehicle wont start or you dont hear any noise from it at all.
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Monday, March 30th, 2009 AT 9:47 PM
Tiny
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I replaced the relay as well, and yes I can hear it when it turns on before I start the motor. Could it be a bad fuel pressure regulator? It is new but I did get it off of ebay and not napa or anthing like that.
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Monday, March 30th, 2009 AT 11:08 PM
Tiny
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Really like to see what the fuel pressure is when it wont start and what it is when it will start. That way we know if its electrical or if its indeed fuel system related.

Could be the coolant temp sensor.
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Tuesday, March 31st, 2009 AT 8:43 AM
Tiny
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Will it start with foot on pedal?

How about cycling key on and off a few times before starting vehicle?
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Tuesday, March 31st, 2009 AT 8:46 AM
Tiny
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Yes if I turn it over and off then over again it'll start right up
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Tuesday, March 31st, 2009 AT 10:19 AM
Tiny
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No! Im saying just on not to start, then off. Sorry.

Do that so you can narrow it down strictly to the fuel system. If that works then the pressure is too low. If it still has to be cranked first thers a different issue.
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Tuesday, March 31st, 2009 AT 12:29 PM
Tiny
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Sorry I'm kinda confused, so I turn the ignition on then off, and then try and start the engine?
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Tuesday, March 31st, 2009 AT 1:27 PM
Tiny
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Turn key on till pumps on. Then turn key off fast and back on so pump runs. Simulating the cranking the vehicle then recranking.

If 2 turns dont work try 3 fast turns to get the pressure high. Does it start?
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Tuesday, March 31st, 2009 AT 4:01 PM
Tiny
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Yea it does. If I get the pressure up it'll start right up
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Tuesday, March 31st, 2009 AT 4:17 PM
Tiny
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So I got a fuel pressure guage today and I put it in and just turned the key on(just to run fuel pump) and there was no psi. Then I turned the engine on and it shot up to 94 psi I think its suppost to be at 55psi. What could the problem be?
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Sunday, April 5th, 2009 AT 12:11 PM
Tiny
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I just ajusted the pressure regulator to 55psi while the engine is running, and if I pull the vaccum hose out it goes to about 60psi, and when I shut off the engine the psi drops to 0. Is this the pump or the regulator?
-thanks
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Sunday, April 5th, 2009 AT 1:44 PM
Tiny
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55 is good. And when the vaccum is pulled at it jumps up that seems right.

And it shouldnt drop to 0 when empty turned off tho.

Could be a bad check valve in the regulator. Or fuel pump.
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Monday, April 6th, 2009 AT 6:54 PM
Tiny
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Is there anyway to check and see which one is failing? The fuel pump is fairly new
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Monday, April 6th, 2009 AT 10:18 PM
Tiny
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Pinch off return line right before assistant turns off key. Does it hold?

If it does the regulator is leaking off the pressure.

If not pinch off supply line. If that stops it then the pump may be bad.

If pinching off supply and return and pressure still goes on suspect issue with injectors.
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Tuesday, April 7th, 2009 AT 6:35 PM
Tiny
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Do I just pinch it off with some pliers or is there something specific I should use?
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Wednesday, April 8th, 2009 AT 12:57 PM
Tiny
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Use hose pinch off pliers. Ask at a autopart store for them.
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Wednesday, April 8th, 2009 AT 1:45 PM

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