Any EFI experts out there? Fuel problem...

[mtm_seven]

Hey Gang,

I'm trying to chase my last EFI problem and need some help.

I have a bastardized setup but I'll try to hash it out.

Vortec 350
700r4
Edelbrock Pro Flo MPI (4 barrel manifold)
FAST XFI retrofit upgrade (to make the edelbrock ODB II self learning)
Stock tank (clean)
new Walbro pump on frame rail pass side
3/8 inlet line from tank to fuel rail (all new and high pressure line)
3/8 return line from regulator to tank (all new)
1 filter after the pump (new)
new sending unit in tank (sock removed)

I think I'm getting air in the system but can't tell if that's my entire problem.

My return line in tank is not below the surface of the fuel so it's "falling" when returned. I believe that's creating aeration in the tank when the fuel level drops even slightly. Then the pump receives air bubbles causing pressure to drop significantly and thus not enough flow for the injectors under heavy load.

Symptoms: Very loud fuel pump, lower than 42-45 psi at rail like the regulator is designed for, falls on face and leans out under heavy acceleration / load.

I'm planning to extend the return line in tank with a piece of hose and a weight to keep it below surface. Is there a trick to dispersing the fuel out of that hose to keep it from agitating in-tank fuel more than necessary? Like a sock or a perforated tube?

If anyone else is running a walbro pump, have you had trouble with it making an unholy screaming sound when you're low on gas?

Does anyone have a different brand / style of pump they can recommend for a mostly stock setup like mine which would be less prone to cavitation when aerated fuel is introduced?