I have a Carter fuel pump(6-8psi/72gph, frame mounted, rotary), does this style of pump need a return line? Pumps great when free flowing, hook the carb upand it puts out little or no pressure or volume, engine starves for fuel. Doesn't matter if the tank(new) is full or almost empty, new lines have been installed with no kinks or collapsing(3/8"). The pump is mounted about 14" away from tank and as close to the bottom of the tank(pick-up goes in from top) as possible. It's getting just enough fuel to run and be driven but when the secondaries are opened the pump just can't keep up. Any ideas or suggestions on set up. Bigger pick up line, tank bottom fuel outlet, in tank low pressure pump?

 

Does your carb have a fuel filter on it? That may be plugged.

 

Well, first of all, that pump will be hard pressed to keep up with a beefy engine. The thing is, all of these electric pumps are cooled by the fuel drawn through them..little demand and they don't cool effectively. Really, the only good way is to run a fuel regulator and return line. I've run allot of combos and had my share of problems so here is my recipe for a problem free fuel system I've discovered over the years:

A good fuel regulator with return line(Do not use a dead head type like the cheap Holleys). I recomend Aeromotive regulators.

A good fuel pump. Again, I recomend Aeromotive but if you wanna go cheap I've also had good luck with the Holley black pumps provided they are run with a good reg and return line.

1/2 line throughout and the pump mounted as close to the tank as possible...these pumps are pushers not pullers.

High flow filter before the pump...again, aeromotive makes some goods ones but so does barry grant and others. A normal filter won't cut it because it will restrict flow.

The above set up will fix any flow prob. you have and feed any engine you want to run. Naturally, you need to make sure there aren't any restrictions in the tank or hard line but thats easy enough to do. Have fun~

 

All the stuff is new from the tank to the carb. I am going to try a return style set up and see if that cures the prob. Thanks guys.

 

a return line will help on any electric pump and will at the least reduce temp, increase pump life, and reduce cavitation at the pump which will help flow. Don't go cheap on the regulator and good luck.

 

Is your tank properly vented? Could be like sucking on a 20oz pop bottle when it runs out of air, it collapses.
You usually only really need a return line when you are regualting pressure and you need somewhere to bleed off the excess.
try running it with the gas cap loose and see what it does. The stock mechanical pumps do not have return lines.
Jimmy

 

Update: Running new fuel lines, #08 AN, new fuel pump(140GPH), return style regulator and all the other goodies to go with the new system.

It is properly vented.

Quote:The stock mechanical pumps do not have return lines.

This is for a Bronco II running a 306CID V8 pushing 350HP, not enough room for any kind of mechanical pump.