T62-1GSR

I have a 96 civic with a GSR motor and a custom turbo kit running 7lbs. I have a skunk 2 jumper harness to convert my car to obd1 and a stock obd1 p72 ecu. My car is throwing a code 43 ( which is a fuel system supply code). My air/fuel guage stays on lean when the car starts and when it idles. When i give the car gas it goes to stoich and stays there. I have replaced the o2 sensor 3 times, replaced the fuel pump to a 255, replaced the fuel lines, injectors, fuel filter, taken off the fuel rail and cleaned it, and new pressure regulator. My car still throws the same code. The car will only throw the code after boost and driving normal. The car is running really rich becuase gas mileage is terrible. I do have a vortech 12:1 fmu in the car. Is it a voltage problem???? At this point im baffled. Any info would help out.