I was just wondering about how everyones' fuel pressure acts. I put an Autometer electric fuel pressure gauge on a while back, and the fuel pressure is at/around 41 psi at idle. I also checked the fuel pressure with a manual gauge before I put on the electric one and got the same thing. When I am at WOT the pressure drops to around 38 psi, and when I am just cruising, or leaving a stop light/sign, the pressure rises from 41 to around 42 then after about half gas it starts to drop again. I have a Holley 255lph in tank fuel pump, and the fuel pressure regulator is the one that comes with the Miniram. Even when I screw the regulator all the way in, the pressure won't go past 42 psi, and the car will bog so bad it will almost die when it is screwed in too far and I go into WOT. I have the Diacom software, and it says that the fuel pump relay voltage is 12.8 or 12.9, but it never strays from those #'s even at WOT. I called TPIS about this a while back and they just said that the aftermarket in-tank fuel pumps can flow more, but only to a certain point, that I would need a physically bigger fuel pump to get any more pressure out of the system. Any thoughts on this would help...

 

TPIS may be correct. You need the most pressure at WOT, and if you're not getting that there is something wrong with the delivery. Your fuel pressure should basically rise from idle until you reach WOT. I don't how much fuel you need or how much that pump will give you, so I can't say for sure that the pump is insufficient.