05-19-2012, 12:49 PM | #1 |
Registered User
Join Date: Mar 2012
Location: San Antonio, TX
Posts: 33
|
Fuel Pressure
OK guys I need a little help. I installed a fuel pressure gauge a month ago and I notice that whne it start up, even after it warm the fuel pressure is right at 5psi. After the run for 15 minutes or more the fuel pressure starts to drop very slowly. It drops all the way down to 2psi after 30-45 minutes. If I rev the engine the fuel pressure never reach back to 3psi, it might only increase .5 psi at most.
New fuel pump and all rubber fuel line replaced. I checked the length of the whole truck for any leaks and nothing. Any help would be greatly appreciate. 1985 C10 350/700R4 |
05-22-2012, 07:00 PM | #2 |
Registered User
Join Date: Mar 2012
Location: San Antonio, TX
Posts: 33
|
Re: Fuel Pressure
Anybody?
Anyone know of a website I might find any answer at? I tried a fuel speciality place but nothing was found after searching.
__________________
Thanks, Edgar Red 1985 C10 Stepside 350/700R4 2014 GMC Sierra Denali 6.2 2015 GMC Sierra 5.3 |
05-22-2012, 09:10 PM | #3 |
Registered User
Join Date: Nov 2011
Location: rock springs wyoming
Posts: 182
|
Re: Fuel Pressure
check your cam lobe where the push rod runs on and the push rod. they might be worn out. when the motor warms up the oil thins out and the the space between the rod and the pump or the cam incresses and u loss pressure.
|
05-22-2012, 09:49 PM | #4 |
Registered User
Join Date: Mar 2012
Location: San Antonio, TX
Posts: 33
|
Re: Fuel Pressure
Thanks, I'll pull the fuel pump and check it out.
__________________
Thanks, Edgar Red 1985 C10 Stepside 350/700R4 2014 GMC Sierra Denali 6.2 2015 GMC Sierra 5.3 |
05-23-2012, 10:30 AM | #5 |
Moderator
Join Date: Oct 2008
Location: Wentworth, NH
Posts: 4,977
|
Re: Fuel Pressure
Check it with a new US made fuel pump.
__________________
1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
And please let us know if and how your repairs were successful. |
05-23-2012, 06:23 PM | #6 |
Registered User
Join Date: Mar 2012
Location: stafford springs ct
Posts: 149
|
Re: Fuel Pressure
is there a running problem also or is this just something you see on the gauge? if it is also a running problem, check for an in-line filter before the pump that may need replacement. good luck.
|
Bookmarks |
|
|