my mallory 4110 fuel pump is only putting out 3 psi.
so before everything it was putting out 9 psi like it should. i installed a 4th gen gas tank. i removed the internal ls1 fuel pump and ran a straight line down with a filter on the end . i also removed the built in regulator from the return line. i also replaced the internal brushes on the mallory 4110 pump with the mallory 3164a rebuild kit.

ive tried adjusting the regulator built into the pump. ive also tried adjustting the holley bypass regulator i have close to the carburetor. the fuel pump is only 2 years old
i need to get this thing on the road by tonight

after i completed the re-install of everything the fuel pressure gauge showed 5.5 psi so i took it onto the street where it instantly when to 2 psi and i havent been able to fix it yet. i need about 6 psi for the car to run

 

You got me, man.

If you pinch the return line will the pressure spike up? That should at least narrow it down to whether the problem is at the regulator or elsewhere.

You're not using a liquid-filled fuel pressure gague, are you? They are all junk. Haven't found one yet that will tell you the truth for more than a few weeks, often bad right out of the box.