85LSburb

iTrader: (1)

I have a 01 Silverado with a 5.3 that looses fuel pressure with key off. Takes a few key cycles for pressure to build. I have pulled the vacuum line off the regulator and no fuel is in the line. The fuel pressure jumps to 58 with the line off. As soon as you shut the key off the pressure drops from 50ish to 0 in about 5 seconds. Any ideas?

FFDP

iTrader: (2)

Bad regulator.

It doesn't have to **** fuel out to still be bad. If it can't hold the pressure, it's the first thing on my list to change.

I wouldn't think it's a check ball in the tank/pump if these trucks even have them.

1FastBrick

iTrader: (17)

It could also be the line on the pump inside the tank.

Mine developed a pinhole leak that was obvious when I pulled the pump for replacement.

01ssreda4

iTrader: (87)

Mine used to do that so I replaced the pump assembly.

85LSburb

iTrader: (1)

Thanks guys. I'm just gonna replace the pump and regulator. It has over 200k on it.

1FastBrick

iTrader: (17)

Good call with that kind of mileage.

Wolftrk99

iTrader: (5)

My 99 has done it the same thing to me at least 3 times and every time it has been the pump. i never really got i to figuring out why it was happening, but there were too many other issues all pump assembly related; inaccurate fuel level signal, delayed start, and random loss of pressure. I had one pump that was providing just enough pressure for the truck to run, never thrpugh a lean code either at the end of that one's life i wasgetting ridiculously good fuel mileage....then i changed it