Fuel Pump Capacity Test

Before performing this test, verify fuel pump pressure. Refer to Test. Use this test in conjunction with the Fuel Pressure Leak Down Test.

1. Release fuel system pressure.
2. Disconnect fuel supply line at fuel rail.
3. Obtain the correct Fuel Line Pressure Test Adapter Tool Hose.
4. Connect the correct Fuel Line Pressure Test Adapter Tool Hose into disconnected fuel supply line. Insert other end of Adaptor Tool Hose into a graduated container.
5. Remove the fuel tank filler cap.
6. Turn the ignition switch to the ON/RUN position.
7. A good Fuel Pump will deliver 1 liter (1.05 qt.) of fuel in a maximum of 35 seconds.
a. If capacity is lower than specification, but Fuel Pump can be heard operating, check for a kinked/damaged fuel supply line somewhere between fuel rail and Fuel Pump.
b. If line is not kinked/damaged, and fuel pressure is OK, but capacity is low, replace fuel filter/pressure regulator assembly.
c. If both fuel pressure and capacity are low, replace the Fuel Pump and the Fuel Filter/Pressure Regulator assemblies.