External fuel pump problem

[sman]

Working on my dads 69 nova, converted to an electric fuel pump setup. Its an external pump, mounted to the frame rail. It runs the car fine and appears to keep pressure "fairly" consistent(within .5lbs). However it makes this strange noise. It sounds like its going from low to high or something, or has a load on it then it goes away. It revs up then slows down, and goes back and forth every few seconds. Pump is brand new, along with filter, lines, regulator, and gauge.

Any ideas, its one of the very few things holding up the car from being done.

[c0ncEpT]

If the fuel pressure is consistent whats the problem. An external pump is going to be inherently noisy.

[sman]

Also, car has about half a tank of gas, so thats not the issue.

[sman]

The pressure isnt perfectly consistent, frankly were afraid its just going to die or something. Ive heard lots of out of tank pumps, but none that do anything like this.

[98blackbeauty]

Maybe pump is to big and regulator is causing the cycle. measure pressure before and after regulator.

[DETROITMUSCLE]

got a regulator on it? how about a return?

[farmington]

is this a efi installation or carb?

[1BADAIR]

electric pumps are ment to push fuel. They should be as close to the tank and as low as possible. mechanical pumps are designed to pull fuel

[sman]

It is below and next to the tank, on a carb application (454 BBC), no way to measure pressure before without undoing a bunch of lines, we can try. There is a regulator taking the pressure down to 5ish lbs. But no return, the regulator doesnt appear to have a spot for it. Im heading out in a bit, ill take a picture.

[sman]

Biggest problem, I was un aware the pump he was trying to use is for an efi setup, 40+lbs. I just happened to have a brand new in the box carter 5psi internally regulated vein style on the shelf in the shop. Gonna throw that on tonight and see where that gets us. Going to pull the regulator off and trying and find a "T" for the pressure gauge.

Just got the fuel pump, 1 axle seal, and a foot a vacuum line then its done!

Amazing that even with a BBC under the hood, there is still SOOO much room to work. Almost makes that motor look small!

[shawnc16]

Typically on the EFI style pumps, you need to run a return back to the tank. Thats probably why you're getting that surging sound. The fuel has nowhere to go once its been regulated down from say 40 to 5 PSI.

[sman]

Yea, he neglected to mention the pump was pushing 40+ psi. Should be driving it home from the shop tonight if this pump solves the problem!

[shawnc16]

Sweet! I love Nova's especially with a BBC sitting pretty in there.

[Gregs_gsxr]

yea !! more pics !!!