chevymec

iTrader: (5)

I just replaced my fuel pump with a pump from TRE. The car didnt run when I got it. I notice that with KOEO the fuel pressure is only 20 psi. . This makes for some long starts. With the motor running it has about 38 psi with vaccum to the regulator and is about 42-44 psi with out vaccum. I havent noticed any fuel in the vaccum line and the system doesnt hold pressure very long after the key is off. Is this normal for a TPI. I have a fuel filter but havent changed it yet.

87zjeff

iTrader: (4)

no, it is not normal. with koeo, the fuel prssure should come up to about 40psi and hold. there is an acceptable bleed off of pressure but i can't remember what it is. you can try changing the filter, but i doubt that is your only problem. clamp off the return line and see if it holds pressure. if not you have an injector leaking or fuel pump not holding pressure. if you clamp the return line and fuel pressure still doesn't come up to at least 50psi, then you probably have a bad fuel pump. 20psi is way to low for a koeo unless it has sat for a while.

jamon8

iTrader: (3)

also try putting 10 psi of vaccum to the fuel press reg and see if it will hold it. it sound like your fpr get a adjustable fpr if its bad

87zjeff

iTrader: (4)

in a koeo situation, putting vacuum to the regulator with a hand pump will not allow the regulator to hold vacuum. so that isn't a good test. you put vacuum to it while the engine is running to check fuel pressure. engine off=no vacuum.

IROCThe5.7L

20 Psi should be enough to start the motor fine. I connected a gage to my rail and got a constant 20 psi with the key foward, and it always started fine. Now I got 40 psi with the key foward and it still starts fine.

chevymec

iTrader: (5)

what did you do to get 40 psi with koeo?