Fuel Pressure: Testing and Inspection

PRESSURE TEST

1. Connect Fuel Pump Pressure Tester to the injection pump end of the fuel line. ("T" is not required).
2. Crank the engine for 10 seconds and read the pressure. Refer to SPECIFICATIONS for the fuel pressure specification. If pump pressure is too low or too high install a new fuel pump.
3. Connect fuel line.



CAPACITY (VOLUME) TEST

1. Disconnect the fuel line at the fuel filter (fuel line is pressurized).
2. Place a container (1/2 liter or 1 pint minimum) at the end of the disconnected fuel line (a piece of hose may be needed on the fuel line end). Crank engine ten seconds. The fuel pump should deliver 1/3 pint of fuel, or more.
3. Perform pressure test if fuel flow is to specification see SPECIFICATIONS.
4. If fuel flow is low, repeat test using a remote non-breakable container of diesel fuel. Remove fuel hose from fuel pump inlet supply line. Connect a length of fuel hose from the fuel supply line to the non-breakable container and repeat Step 3. If fuel flow is to specification, the problem is either a plugged fuel/water separator or, a kinked or leaking fuel hose. Service as necessary.
5. If fuel flow does not meet specification, replace fuel pump.