bloo4.6

iTrader: (8)

have a few questions my car has been acting kinda funny lately and so i decided to hook up a fuel pressure gauge to it and its running around 58psi at idle but when i get up around 5k it goes down to around 40 psi. its a walbro 255 pump and i decided to pull the filter and its not to bad you can tell its time to change, could a dirty filter cause this or is it the pump ??? Its also running a filter that ive never seen before it has a return line on the side coming from the tank, when i looked up the filter it was off of a 03 vette

showstoMpinSS

iTrader: (2)

x2....

FasTimeSS

iTrader: (47)

thats ur problem mine did that with a stock pump... n/a and on n20

bloo4.6

iTrader: (8)

filter or the pump?

showstoMpinSS

iTrader: (2)

im replacing both, filter is 9.99 from autozone

bloo4.6

iTrader: (8)

well auto zone wants 86.00 bucks for my filter ???

AffordableAutoworks

Yes, a clogged fuel filter can cause the pressure to lower. This is the least expensive to change first. It should not be that expensive though. Where are you located?

bloo4.6

iTrader: (8)

ft worth tx, just replaced the filter and pressure still drop to 30 psi give or take at WOT, guess ill be ordering another walbro 255

AffordableAutoworks

If you get frustrated with it bring it to the shop and we can pinpoint the issue.

cambirdracing

iTrader: (4)

When all of your injectors are open, its going to lose fuel pressure. Kinda like when you open the blow gun on the end of your air hose, the line loses air pressure. I don't know if 18 psi loss is normal or not, but it's going to lose some.

mike171562

iTrader: (4)

I had this problem with my walbro and it turned out the hose had popped off the pump, I would check that before I bought a new one.

bloo4.6

iTrader: (8)

yeah the car been giving me hell starting so i dont think it just losing pressure at wot throttle, i had a new pump overnighted already and just going to install a new one tonight