this is yet another question i have:

i am about to put the new electric fuel pump and regulator in.
my question is, do i need to run a return line for the electric fuel pump? because it will always be pumping the same volume of fuel regardless of engine speed, which the way i figured it would mean its pumping too much at idle/light throttle.

also, if i have to run a return line, do i then put the regulator on the return side?

and..... if i run a return line, do i just put it back into the inlet line (between the tank and the pump) or does it have to go back into the tank?

thanks in advance...

Dude, the fuel pump will stop pumping when the needle + seat closes in the carbs. What carbs are these if carbs at all?

if you run a pump next to the tank and the reg in the engine bay then you will put the reg on the current fuel line and run a return line off he reg. Return line will have to go to the tank.

Most of the N/A setups I've seen dont run a reg and just kinda stall the pump at low revs. I dont know if this is bad for the pump or what

Its not bad for the pump at all, when setting the reg, you just have to make sure you maintain enough pressure through the higher rev range and not too much to cause the needle + seat to leak. Is this for carbs? What carbs?

yeah I'm thinking about the malpassi rising rate regs, the redline style dont even have a return line

yeh its for twin 40DCOEs.
as tyrie said i was only worried about that it would load the pump up when the needle shut and there was nowhere for the fuel to go, effectivly stalling the pump.

its not turboed and ive been told i dont need anymore than 1.5 psi.

Ive got my 42DCOE's set at 2psi at the moment, havent revved it hard enough to see if i need more, near 5,000rpm it drops to 1.5psi, im happy with that. What pump is it, if its a low psi then it shouldnt be a problem, they are designed to run like this.

yeh thanks WhiteSedan. its a facet blue pump. its certainly not a high pressure pump, or is it big enough to even look like it would run an EFI car.

ill forget about the return line...

so do you run a regulator or not?

Yeah ive got a malpassi carb regulator. You have the correct pump there mate, i guess you got the reg with the pump, run the reg.

To run a return on webers is pretty expensive, offroad vehicles modify their webers to do this because of fueling issues, involves machining etc.

Thanks for that mate.

shows what my auto techer knows....