Installed a factory fuel pump and twice I had troubles starting?

R.RAMOS

MEMBER
2001 CHEVROLET SILVERADO
V8
2WD
AUTOMATIC
105,000 MILES

I recently installed a factory fuel pump and twice I had troubles starting in the morning. When I come back from work the trucks starts like new.I can hear the fuel pump run and hear fuel pressure build at fuel ports.I have checked the fuel pressure sensor at fuel port by removing vent hose and fuel does not come out. This is what 2 gm dealers told me to do to check for faulty fuel pressure valve. Battery is strong and when I turn key its sounds like it is going to turn over but once I let go of the ignition it stops. All this trouble is on a 2001 silverado 2500 hd 6.0 a/t
2wd ext cab long bed w/ about 105k miles. Thanks
for your help

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

It does sounds like an issue with the fuel pressure regulator.
As you only have the issue when its cold, the internals of the regulator could stick when its cold but as everything warms up it gets free does not have any sticking issue.

You can do a fuel pressure test when its cold and another one when its warm.
That way you will be able to see if the pressure is lower when cold. And if it is then you will know that it is the regulator.

You should have 55-62 PSI of fuel pressure with the key on and engine off.

Here is a helpful video of how to test the fuel pressure:

https://youtu.be/aITQclp7zIE

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

I have attached the fuel pressure regulator diagrams for your reference.
Please let me know of any questions.

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