So how would you guys check to see if my fuel pump is going bad? My truck seems to run fine at idle and if I slowly get on it. But pulling hills and if I floor the truck it has no where near the power it had. Everything in and on the motor is only 2 and a half years old and 35000 miles on it. Did a buzz test all the injectors sounded fine. I have an ITP regulated return kit that i just put on it. And the factory fuel pump does have 260000 miles on it. So could that be it? or did I just get a junk HPOP on this new motor.

 

You can clamp a cheap guage to the drain tube on your fuel filter and see where your pressure is at.

 

What should the pressure be at on a WOT run with a 80 horse DP tune or even stock for that matter?

 

IIRC the fuel pump supplys a constant pressure it shoud be around 50 psi.

 

Ahh I see, I have my fuel pressure at idle set at 68-70 psi. So that drops to 50 when running? And could a worn pump cause this problem im having it seems like it can supply enough fuel when i slowly get on it. But if I stab the accelerator it just falls on its face.

 

Fuel pressure shouldn't drop when accelerating, or at least it shouldn't drop more than a couple of PSI, especially on stock injectors. So whatever pressure you set the regulator at, the fuel pump should continuously supply that same pressure, even during acceleration.

Jim threw out the 50 psi number because most bone stock trucks usually sit somewhere around that fuel pressure. Since your truck has a regulated return, and an adjustable regulator, you obviously are running different pressures. Setting it around 70 psi is fine, but it should stay that way even when at WOT.

Is it possible that your fuel pump is weak? Sure. But the only way to know for sure is to run the gauge from under the hood and somewhere visible while you are driving. If you just want something temporary, get some fuel line and 1/8" NPT adapters and run the line from the regulator to a remote mounted gauge sticking out of the hood (don't run it inside the cab, you don't want a fuel line to burst inside).

Other than that, you would have to check other possible issues such as oil pressure and so on.