Trying to find a low pressure quiet reliable fuel pump for a 240z resto however; not much out there that is quiet.

I was thinking that maybe lowering the pressure of a 280z FI pump may be do-able:

- remove some of the cylinders in the impeller to reduce flow (item 2 below)

- lower relief valve pressure (item 3 below)

These mods and a good low pressure FPR up by the carb may be suitable, reliable and quiet. Any input before Count Dracula and I go down to the lab...Fun Time.

Edited July 17, 201113 yr by Blue

You could put a large return line at the carbs with a low pressure regulator just past the carbs. In other words bypass most of the volume from the pump back to the tank to lower the pressure.

Steve

Tinker with the pump and you might as well toss it in the garbage.Just reg it at the carb(s).That pump will keep the fuel supply on the cool side.

Tinker with the pump and you might as well toss it in the garbage.Just reg it at the carb(s).That pump will keep the fuel supply on the cool side.

:tapemouth Do not destroy an EFI pump by trying to modify it. I agree with Z train.

I ran an efi pump with a carb once, and like Doradox, I ran a return line back to the tank, in fact it was already there and it was a 1/4 inch line. I ran a Holley carburetor and the resulting pressure didn't flood the carb. The ONLY mod I made was to cut off the restriction at the end of the return fuel line rail, so there was no restriction in the return line that would, for a low pressure pump, provide the carb with the needed 4-4.5 psi fuel pressure.

Cheers mate.

Is that a working OEM pump you're about to mod? :tapemouth

Why not use the pump of some common, more modern EFI car? Maybe a Chevy Cobalt. Sell your working pump on Ebay to someone with a 280, if you don't want/need it. Do it for karma's sake! :classic: