L31MaxExpress
I'm Awesome
recently i posted about my fuel pressure, it's similar to yours, and i have determined that my next step is replacing the fuel pump. if that doesn't fix it, my recently installed fuel injection spider/pressure regulator assembly is at fault.
Don't overlook the electrical. The OEM fuel pump wiring was actually not adequate when NEW to get all the OEM pumps capacity much less now ~25 years later. You can only test the voltage reaching the pump with the pump actually pumping fuel, I was only seeing 10.5 volts at the wiring before the pump connector at the pump with the engine running prior to the Racetronix upgrade. After I was seeing 13.5 with the alternator charging at 13.8. I was running the OEM upgrade spider at 70 psi at the time.