lift pump

[THE CLEANER]

Hi All, i have a 98. 5 24 valve and an ez box with some other little mod's. Just wondering if adding more fuel to this pump will kill it faster than stock? Also what are the signs of a bad pump. What would be a good replacement if the stock one goes. As you can tell i dont have a fuel pressure gauge yet. TIA

 

[RobbyRam]

My pump had 3psi at WOT @ 70K miles so the dealer replaced it , and now it barely drops below 13psi at WOT.



However the new lift pump (now just two weeks old) only makes the buzzing noise when I first turn the key on in the mornings.



I hooked up BriarHoppers fuel pump test gauge and it reads 3psi with just the key on in the mornings, (read 10 psi two weeks ago)then for the rest of the day there's no noise and "0" psi when I just turn the key in the on position.



I can hear the fuel tank give that 'suck-in-pop' sound every time and the gauge, after starting, reads 15 psi at idle and the truck runs great, but,when warm, it cranks over now a couple more revolutions than it did even with my old pump that had 5psi every time I just turned the key on.



Is my new lift pump going south already?

 

[Bigsaint]

From what I've read here, the 98. 5's were/are notorious for VP44 faliures. I'd get a FP gauge and see what you have at idle and while putting a load on the engine while driving. I'm of the opinion that using more fuel won't hurt the lift pump, other members have different views. Adding more fuel will show a lift pumps weak points. For example, if the pump you have now is seeing 3 psi's at full throttle, under a load, adding a fueling box may bring those same numbers to 0 psi's or even vacuum numbers as the injection pump is now trying to suck the fuel it requires. This is a bad thing as the VP44 uses fuel for lubrication.



Things to look for with a failing pump are slowly declining psi's and fluctuating psi's under steady throttle.



Scott W.