walbro 255 pressure at the rail..........?

[billyjo]

I have a adjustable regulator after the rails and I set it to 58psi

Bill

[TAQuickness]

70psi sounds a bit high for just a fuel pump swap. 60psi - 65psi is what most folks see.

After my Racetronix install (pump & harness) I average 63psi at idle. WOT's another story...

[mr.prick]

well now i`m wondering what would give me higher fuel pressure.
maybe the sock filter fell off in the tank or a bad relay?

[DrX]

Have you tried a different gauge? 70 psi sounds high unless you are using a voltage booster and it is always on or the intank FPR has been modified/messed up.

[mr.prick]

i am using a mechanical gauge.
i `m not sure what could go wrong with it to show 10 psi
more than it should, but i guess it`s a possibility.
and i swear that i was seeing 58-60 psi before but
maybe i was reading it wrong LOL. (increments of 20)
i just have the pump , no hot wire kit.
also my voltage is 13-13.5 i`m pretty sure thats normal.
i also found out you don`t want to go around corners really hard
with just 1/16 of a tank of gas .
this is NOT a new pump. (28,000 miles)

[joecar]

If you're sure that you saw 60 psi on this pump and now see 70 psi, then the FPR may be faulty (as DrX said) or the return pipe may be restricted (located on the outlet side of the fuel filter and goes back to the top of the pump assembly where the regulator is located).

[mr.prick]

i hold pressure with the car off and have 60PSI with the key on......?

[joecar]

i hold pressure with the car off and have 60PSI with the key on......?

Holding pressure with engine off means: regulator is not leaking, injectors are not leaking.

Key on is not sufficient since pump runs only 2 seconds each time key is cycled to on... would have to cycle it at least 5 times... but FPR is static after pump stops running (i.e. it dumps a little pressure and then stays static)...

you want to see pressure while engine is running, because then FPR and pump are under dynamic conditions...

your pump is probably good, but your FPR may be sticking or the return line may be retricted... but they may also be ok... I said may...

[mr.prick]

oh man i don`t want to drop the fuel tank

[joecar]

Thinking Out Loud (TOL)...

you might be able to check the return line by disconnecting it at the T and blowing clean compressed air regulated to say 72 psi... if air can go in then FPR/pipe should be ok, if air seems to not want to go in, then FPR/pipe may be stuck...

(warning: service manual says that fuel pressure must not exceed 75 psi otherwise damage may occur)

I don't know if this warning is refering to damage to [GM] pump, regulator, or nylon lines.

Does anyone think 70 psi might be ok, a little on the high side, but ok...?

Are you sure your pressure gauge is reading right...?