swapped in my carbed 3.4 about 2 months ago and left the V6 fuel pump in there. I have an adjustable fuel pressure regulator and it was easy to set the pressure to where I need it (about 6psi). My concern is the V6 pump is designed to generate 40+psi. It's used to having a bunch of pressure behind it, but now it pretty much runs with no pressure behind it. My fuel pressure regulator recirculates gas back to the tank, so there is a major backflow to the tank since only 6psi is needed. Haven't had any problems after driving it for 2 months, but is this condition going to wear the pump prematurely?
Absolutey not Ditch. The pump is running with virtually no pressure on it. The pump is simply coasting along. On mine I can hardly hear it run. 3rd season and no signs of problems.
Probably won't have any effect at all. Remember, the main cooling of the pump is by the fuel flowing through it. The volume of fuel isn't changed since that's a function of the pump impeller design. The main problem would be what the regulator is rated for inlet pressure. If it's lower than the 45PSI the pump produces you may eventually have problems with the regulator failing.
I can't remember what regulator I have, it wasn't the holley one. I got it from summit. It has an inlet port, return to tank port, and multiple output ports. I guess the extra output ports are for if you need to fuel something else (second carb, fuel jet for nitrous, etc). Anyway, it has a main adjustment bolt on top which you turn to change the outgoing pressure. I read the pressure by a pressure guage installed on the line between the regulator and carb. Very simple unit.
