FDS12 - Check Fuel Return System

^ Key Off.

^ Observe Service Precautions to avoid fuel spillage and injury.

^ Fuel return line disconnected at the fuel pressure regulator.

^ Check the fuel return system for restriction due to blockage, kinking, or pinching.

^ Disconnect the fuel return line near the fuel tank.

^ Apply 3-5 psi regulated shop air to the return line at the pressure regulator side.

^ Does air flow freely through the line?

YES -- Replace fuel pump assembly. Repeat Test Step FDS2 for verification. FDS2 - Fuel Pressure Test

NO -- Service the fuel return line. Reconnect fuel line. Repeat Test Step FDS2 for verification. FDS2 - Fuel Pressure Test