fuel pump promblem?

[wshI_hd_1]

Ok, heres the promblem...at idle and normal driving condition my fuel pressure is 40# but once i hit WOT the fuel pressure shoots down to 20#. Is this the fuel pump or can it be the FPR (billet adjustable).I have no idea what size pump i have but what size should i run with the mods in my sig? (also, i have 24# injectors if it helps)...
thanks in advance.

 

[Stang8URMPRT]

Yes, it could possibly be your fuel pump. They are 90lph stock, which is good for about 300 hp. You look to be well over that with your parts. Go with a 190 or 255 and a new fuel filter. What seems to be happening when you go WOT and the fuel demand increases, your fuel pump cannot keep up with the demand, thus dropping pressure.

Nick

 

[HISSIN50]

but if the FPR is on the outs, you can have a 100 GPH pump running and the pressure will not be to spec (the FPR is returning too much fuel).

one can carefully crimp the return line to try to determine if the pump or FPR is at fault.

good luck.