hey i just got the mallory 4309 fuel pressure regulator and when i recieved it there was this little metal like spacer piece so to say... and the sheet of paper said to take off nut take out spring and plunger discard spring and put this metal pin deal in instead and reinstall plunger and nut.... are they talking about for the electro fuel pumps or the regulator itself... i'm confues cause the picture shows a fuel pump but i ordered the regulator and it came with that... ??? also why is it that when i screw in a 3/8 thread into it goes good half way then gets hard like its startin to cross thread.... and one more... what vaccum line am i suppose to hook the vaccum port up too ?? or do i just plug it... need help quick.... cars all tore apart waitin for me ... thx



vetter

 

The pin is for a Mallory fuel pump that can be used with that regulator. It bypasses the fuel pump internal regulator. Unless using that fuel pump don't worry about it.

The 3/8 threads are National Pipe Thread (NPT) and are tapered. The more it screws in the tighter and more leak proof the seal becomes. Use some PST on the threads too.

For a carb setup leave the vacuum port open to the air. For safety I run a small line from that port to a location lower then the side of the engine. This is away from the headers and such. A fuel pressure regulator failure mode is for the diaphram to get a hole in it. This will cause fuel to spray out of the vac port.

RBob.