mpk490p

i just fitted a 4110 pump, i already had a 4309 regulator was jump upgrading the pump, i fitted the additional spacer needed so the pump has no bypass, ran it up and it seemed fine until i looked at my fuel pressure!
i run 4.5 psi with my 51ida
the prsseure i got wouldnt sit below 12psi!! the allen key on the regulator did little to nothing and fuel with flowing down my carbs

im using stock gsl-se lines so 8mm feed and 6mm return do i need to up the return?

82FanTC

iTrader: (9)

I just installed the same setup yesterday and had the same problem. I couldn't get the pressure below 9!

I re-installed my old holley regulator without a return and got it back down to 3.

Hopefully someone can chime in with a solution cause I know the mallory fuel pumps tend to burn up without a return.

82FanTC

iTrader: (9)

and I did not remove the by pass plug as it was not mentioned for the Comp 70 series pump only the Comp 110 and 140 were.

should I remove the bypass plug??

82FanTC

iTrader: (9)

Here is what the folks at Mallory had to say

"The Mallory regulator is well designed and should work correctly. There are two probable causes for your problem: regulator malfunction or return line restriction. I am not sure but I suspect that the Holley regulator is not a bypass type. If not, then it is possible you have a restriction in the return line. If the Holley is bypass-type - then, no.

The instructions point out that if you remove the adjustment screw completely, you should get pressure below 3 psi. Please try this. If not, try returning the fuel into a can instead of the fuel tank and see what the pressure is - adjustment screw still out. If it remains high, the regulator appears to be sticking. If not, the return line would seem to be the problem.

One last note - please verify that you are using the correct inlet and outlet ports on the regulator.............."

Hyper4mance2k

iTrader: (40)

that's due to a clogged return line that is very common with all FB's... plus the return line is just way to small. it should always be at least the same size as the feed line when you are using a bypass style FPR. The holly nonbypass style regulators work, but they don't last very long and they put undue stress on the fuel pump which causes the fuel to cativate, heat up, and the pump will wear faster.

AcidAngel7477

iTrader: (16)

what do you recommend using..hyper4mance??

:AA:

mpk490p

thanks for that, im just gonna bite the bullet and fit 10mm feed and return lines, i have a spare tank pick up so i can get that modified off the car that way it will cope with my 51ida and eventualy a bridgy

mpk490p

did you resolve your problem?
I've still to fit my 3/8 pipe planning on doing it in the next couple of weeks

82FanTC

iTrader: (9)

Yes I have since gone to a 3/8 feed and 5/16 return with an -SE pickup. Pressure stable at 2.5 psi

mpk490p

sweet, been having fuel starvation for so long now forget what its like to run WOT in 4th and 5th!