low fuel pressure

[killa89trans]

Formula is losing fuel pressure, within ten seconds lose fuel pressure after priming it once. thinking fuel pump or sending unit depending on where the check ball is located. pulled vac. line of regulator n looks fine. hooked fuel pressure gauge up and noticed primed it once and it hit 40psi but drops.

[Gregs_gsxr]

bad or corroded connections, but sound like the pump is going bad

[WMCCjames]

Factory pump or aftermarket?

[killa89trans]

its def. aftermarket... i just bought the car in february. they cut a whole in the hatch and replaced the fuel pump. had to bend the level sensor so it was accurate. but im not sure when they replaced the pump. i priced some pumps, and hav priced pumps with sending units. its kinda expensive at the moment.

[Gregs_gsxr]

I wouldnt chance driving it until you replace the pump check all the connections, specially electrical, the connections could be good until the pump puts a load on it and it quits cause your not getting enough current.

[meissen]

It's one of three things - the check valve in the fuel pump is bad, the diaphragm in the fuel regulator is bad, or your injectors are leaking. I would think it's either the pump or the regulator. If you pulled the vacuum line off of the regulator and it wasn't wet with fuel then it's your pump.

[WMCCjames]

If it's an aftermarket pump it most likely doesn't have a check valve in it. Mine drops fuel pressure to zero as soon as it stop running....been like that for 6 years.

[killa89trans]

So, if its aftermarket it doesnt have a check valve? at least they hacked it so pumps easy replacement i was hoping the check valve wasnt in the sending unit. but yeah it cranks for a good 5-6sec. before it starts then after it starts it runs n drives fine. i gotta like the upgrade from a 3rd gen 305 5speed with 3.42s to a lt1 auto 3.73s

[WMCCjames]

So, if its aftermarket it doesnt have a check valve? at least they hacked it so pumps easy replacement i was hoping the check valve wasnt in the sending unit. but yeah it cranks for a good 5-6sec. before it starts then after it starts it runs n drives fine. i gotta like the upgrade from a 3rd gen 305 5speed with 3.42s to a lt1 auto 3.73s

305 to an LT1 isn't much of an upgrade...








....oh no he didn't just say that......

LOL

[killa89trans]

lol alot different getting up to cruising speed. but next is ls motor...

[Sic96]

If it's an aftermarket pump it most likely doesn't have a check valve in it. Mine drops fuel pressure to zero as soon as it stop running....been like that for 6 years.

Mine does the exact same thing! Runs consistent at around 42-43psi, WOT is about 50psi, shut it off, and it hits 0 within 10 seconds. It's done this for almost 2 years now. Does NOT mean the pump is going, just a possiblility.

[meissen]

True if it's aftermarket that changes the rules.

[killa89trans]

what kind of pump is recommended? a/c delco? it cranking for a period of time before starting/ having to prime it a few times before starting kind of bugs me.

[WMCCjames]

what kind of pump is recommended? a/c delco? it cranking for a period of time before starting/ having to prime it a few times before starting kind of bugs me.

Turn the ignition on and wait for the pump to finish priming, about 3 seconds, then fire it up. It should fire up right away.

[StoveBolts]

Turn the ignition on and wait for the pump to finish priming, about 3 seconds, then fire it up. It should fire up right away.

Yup, and if it don't start up right away, then do it twice before cranking lol!