I got a pressure test gauge as well. (Borrowing one from the boat was a joke BTW) I got the same results as jet driver. Turn the key on and then it goes to 60 than zero. Start the motor and it idles around 52 and WOT it goes to about 60. It does slowly leak down though as Wally said. Looks like I'm doing my pump too Jetdriver. I won'er what that internal pump costs? Thanks for all the suggestions everyone!
...... Start the motor and it idles around 52 and WOT it goes to about 60. It does slowly leak down though as Wally said........!
Don't know what kind of truck you have, but I would suggest looking up your fuel pressure specs. A typical port EFI system runs at 35-37 psi at idle and as much as maybe 42-45 under full load. Unless the reading you gave above are with the fuel pressure regulator vacuum signal line disconnected, they are too high.
I got a pressure test gauge as well. (Borrowing one from the boat was a joke BTW) I got the same results as jet driver. Turn the key on and then it goes to 60 than zero. Start the motor and it idles around 52 and WOT it goes to about 60. It does slowly leak down though as Wally said. Looks like I'm doing my pump too Jetdriver. I won'er what that internal pump costs? Thanks for all the suggestions everyone!
Just picked up my pump and wire harness and filter from Napa for 225.00. Ill install tonight or tomorrow afternoon. Let you guys know how it goes.
'99 c/k Tahoe 5.0 and 5.7 liter Central SFI
60-66 psi with pump commanded on
55-60 hold pressure when pump shuts off
other possible causes if the pump doesn't fix it (which I'm pretty sure it will) are fuel pressure regulator leaking down, leaking fuel injector / stuck on. When you change the fuel pump I'd also change the filter even it has just been changed recently.
Jay
ok well took me 2 1/2 hours tonight but the fuel pump and filter are changed. Tahoe fired right up now and checked everything with the pressure guage and it holds good pressure now. Thanks everyone for all the help.
P.S. I wont do that again by myself especially with 3/4 of a tank in it. Man that was heavy.
Shawn
ok well took me 2 1/2 hours tonight but the fuel pump and filter are changed. Tahoe fired right up now and checked everything with the pressure guage and it holds good pressure now. Thanks everyone for all the help.
P.S. I wont do that again by myself especially with 3/4 of a tank in it. Man that was heavy.
Shawn
i told you to get a buddy to help,lol. kinda unstable with fuel sloshing around isn't it! did the fuel pressure hold steady after you replaced the pump when you first turn the key on?if it did ,i'd say ya fixed her.let us know
i told you to get a buddy to help,lol. kinda unstable with fuel sloshing around isn't it! did the fuel pressure hold steady after you replaced the pump when you first turn the key on?if it did ,i'd say ya fixed her.let us know
Yeah it sure did! Im so glad this is fixed! Thanks again for all your help.
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