I have 88IROC VIN 8 motor and only getting 10 PSI to the fuel rail. I have changed the fuel pump, (twice), fuel filter, fuel regulator, MAF Sensor, water temp. sensor, and fan relays.
There is zero fuel pressure in the rail, it bleeds off when the pump stops running. Where is the pressure going? When I put 12 volts to PIN "G" the pump will run and all I get is 10 PSI at the fuel rail test port.
OK, now what do I do next?

OK, I fixed the problem. The connecting hose from the fuel pump to the tube had a small hole in it. I vacuum check the hose and it checked out OK, BUT, if I apply pressure to the hose it would open up and the fuel would not pressurize the line to the TPI. The Fuel was just recircuitulating inside the tank.
Just a little IN-FO to you all to make sure that a rubber hose doesn,t cause you as much trouble as it did me.