(1993 Nissan 300zx Twin Turbo 2+2 500rwhp fully built motor)
A few months ago my fuel pump completely gave up so i replaced it with a new TT pump, the old one was a 255 lph walbaro.. After i replaced the pump my car felt better than before i had great power & throttle response yay! about 2 weeks later i noticed my fuel pressure was responding high with such light throttle raising to 55 psi (barley touching gas pedal) so i assumed the FPR couldn't compensate with the bigger stock fuel pump so i replaced the regulator with OEM FPR. That solved the problem for 2 days until i started smelling fuel when i had the heater on, so i popped the hood and i see fuel leaking out of the FPR HOSE (i forgot to clamp!) also my Phantom fuel pressure gauge was acting weird at idle it would usually sit at 40 PSI steady & because of the fuel leak the gauge was fluctuating from 35 - 40 psi at idle. so i fixed the leak but still my fuel pressure gauge is fluctuating from 35 - 40 psi and the high fuel pressure at low rpm / light throttle is back !? while boosting (20 psi) the fuel pressure does not spike or bleed down it usually shoots to about 60 psi WOT and stays there until i back off the throttle.. so now i am back to the same problem i had before except now if the car has sat for more than 10 hours overnight when i go to start it i usually turn the ignition on for 30 secs before starting, my fuel pressure shoots up to 40 psi (as normal) but then bleeds off slowly to 10 psi !! but car still starts up.. i am stumped! the fuel pressure damper is fine i had it check by local Z shop.. i am under the impression that who ever did the swap to my Z maybe left the N/A fuel pump controller in and therefore upgrading to the TT fuel pump (255 to tt) not only caused the FPR to blow but still can't compensate with the bigger 3 speed pump and therefor causing these issues i am having.. any help would be appreciated!!! thank you!
22:50:58 02/22/13
