Fuel Pressure Help!

Jwoo · Post by **Jwoo** » Tue May 01, 2007 11:02 pm

hey guys any experiences of very low fuel pressure like 10-15psi at idle? i've check the fuel sytem and it looks like the fuel pump housing, the pump itself seems to be fine, but i think there must be a leak somewhere in the housing itself. any suggestions or similar experiences? btw my walbro pump is fine and the dealer only sells the whole fuel pump assembly(includes pump and housing),$240

Post by **PrecisionBoost** » Tue May 01, 2007 11:18 pm

why do you assume its a leak???

First thing I would look at is the pressure regulator

daewoomofo · Post by **daewoomofo** » Tue May 01, 2007 11:46 pm

also how old is the fuel filter?

Jwoo · Post by **Jwoo** » Tue May 01, 2007 11:47 pm

i checked the regulator and it works there is something strange going on, also i was wondering if you have any suggestions on a fuel management set-up for my turbo project? i already have some nubira injectors and a safc-ll, and gm 2bar map sensor any other suggestions? thanks

Jwoo · Post by **Jwoo** » Wed May 02, 2007 12:10 am

i just replaced fuel filter and still same thing

Jwoo · Post by **Jwoo** » Wed May 02, 2007 12:11 am

injectors as well

Post by **Efratech** » Wed May 02, 2007 3:22 am

you using standard pressure regulator?

Post by **PrecisionBoost** » Wed May 02, 2007 5:07 am

You should definitly invest in an adjustable fuel pressure regulator

Are you smelling a strong odor of gasoline???

Even a small leak will be very noticeable.... I still have to think it's the fuel pressure regulator.

I would expect to see something in the range of 30psi ( 2bar) at idle and 45psi (3bar) at full load.

I suppose you could also have a vacuum leak.... since the regulator changes pressure via vacuum reference (although I'd expect it to run higher than 15psi with the vacuum line disconnected )

Jwoo · Post by **Jwoo** » Thu May 03, 2007 3:42 pm

we tested the fuel pressure regulator and its still held when we cut fuel off to it, and i do have an fmu as well but my fuel pressure before this problem appeared, was too high(70-90psi on full throttle, the a$$h0le shop that i bought it from ordered the wrong disc which was a 12 to 1) so i disconnected and the car has been running decently since until now, a little over a year.

Jwoo · Post by **Jwoo** » Thu May 03, 2007 3:45 pm

yes standard fuel press regulator

Mad MAX · Post by **Mad MAX** » Sat May 26, 2007 7:42 pm

How to test fuel pressure regulator?
Thanks.

GsiTurbo · Post by **GsiTurbo** » Sun May 27, 2007 2:44 am

You need fuel pressure gauge which you would hook up to the Greiger (? spelling) valve on the fuel rail. You startup the car and record the pressure at idle, and for example 3000rpm. Then you remove the vacuum line from the factory fuel pressure regulator and repeat the test. You should see much higer pressure at idle, and 'possibly' higher pressure at 3000rpm.