need help!

my fuel pressure is at 70 psi during idle, and it drops to 65 when I am on the gas, even with 5 psi of boost, fuel pressure still drop to 65, I am running a brand new walbro 255 high pressure fuel pump and a bosch inline pump, this explain the higher fuel pressure, from my understanding, fuel pressure should increase the same psi as boost psi, I switch out my 1600cc injectors with 1000cc running on E85, now idle is a lot more smoother, but we are running out fuel around 7500 rpm, and I am getting a boost creep running on my 8lb waste gate spring. help!!

 

What kind of kit and what kind of fuel pressure regulator

 

I am running LoveFab gt1 kit with gt35 turbo, I ran with AEM FRP now I switched back to the stock FRP.

 

I'd put a boost gauge on the line that runs to the FPR because when it sees boost, it should up the fuel pressure. Either its not seeing boost or its not working.

 

how much voltage do you have at your pumps? upgrade the power wire and ground to the fuel pumps, use the existing power wire to trigger a relay!

 

The Walbro pumps run out of umph at higher pressures. If you run the larger injectors at lower pressure you may improve the situation.
Many of us have had to change out the pumps for new ones because our original pumps go bad at high pressure/high demand. It is almost as if the mfgs supply Chinese generic copy pumps or something.

 

the Walbro pump is running on factory wiring, the other bosch pump gets power directly from the battery into a relay that gets turn on from factory pump signal.

so far, I like how 1000cc are running very smooth, we just need few more psi of additional fuel pressure during boost.