Im having an issue where the motor is priming to 40psi and idles at 80psi,i have a fuel pressure gauge on the fuel filter(know working)
1993 civic dx
stock fuel rail, fpr, fuel filter, precision injectors.
so for ive tried a stock and aem FPR both known working
Blown out the return line.
Car has a new fuel filter 2 months old on it.
walbro 255 fuel pump.(pulled from tank, bag was clean)
My question is could a bad pump cause high pressure? or where else should i look?

Thanks for the help.

 

Going to try a new fuel filter today any other suggestions?

 

EDIT: Misread the origonal post.

 

maybe a clogged fuel return line.....

 

You're running a 255 with no tune? Here's an idea - try swapping back to an OEM pump, see if that helps your problem.

 

Thats what I thought at first but that wouldnt explain 40 at prime and 80psi at idle. If it were a clogged return it would be max psi, or very close, all the time. I would think...

Why would he need a tune if he still had stock injectors, stock rail, and stock FPR or some other means of regulating the pressure to stock level?

OP check for a vac leak going to the regulator.

 

Sorry yes car is street tuned on neptune. Worked fine with the 255 before i rebuild the motor. idle dropped to 75psi today so im guessing the fuel rail has a clog somewhere.

maybe a clogged fuel return line.....
already blew compressed air through it.

 

vacuum hoses are all good and zip-tied.

 

Turns out the walbro was on its death bed while out driving tonight it all the sudden died. Would not restart. No fuel pump prime. so on the side of the road i swapped in my spare ebay pump. got it running enough to drive home. pressure is now at 40 psi. New pump on order. im guessing because it sat for 2 months when the old motor blew the drain-back valve stuck shut causing the high fuel pressure.

 

Fuel probably dried inside and clogged something or something was stuck

 

glad you found it.. i was rackin my brain try to figure out the issue

 

Yea it was really strange!
Hopefully the new walbro doesnt die quickly. but in event it does ill be keeping the spare cheapo one handy.

 

Soo im really confused. when i swapped in the generic ebay pump it read 40 psi at idle.
now with a new walbro fuel pressure is back at 80psi.
only think i can think of left is clog in the return fitting to the tank on my hanger?

although that doesnt explain how the fleebay 255lph pump would read 40 psi?? but walbro 255 is 80psi?