i have a 4110 Mallory pump and 4309 regulator, i was using a facet red top pump with the same regulator with no issues (4psi) i changed the pump to the Mallory and i can't get anymore then 1.5psi i'm using stock lines 8mm feed and 6mm return doess the pump need a rebuild? (brought second hand) is it a line size issue? it's feeding a street port 13b 51IDA with extended fuel bowl
thanks
Mark

 

If everything else is the same as it was when you had correct fuel pressure...I would think the pump is bad or the electrical connection is not making good contact and voltage is not high enough. I'm betting on the used pump.

 

yep the pump died on me today the morning of my planned drag racing!
swap to the old pump i had and got 3 runs in, will a rebuild kit sort it out or is it trash? it runs but i get no pressure