Injector Leak Down Test

4. INJECTOR LEAK TEST: (Perform with the fuel pressure gauge still connected)

A. Allow the engine to cool to room temperature.
B. Turn the ignition switch "ON" to cycle the fuel pump on for 5 SECONDS.
C. Turn the ignition switch "OFF" after 5 SECONDS.
D. Use fuel hose pinching pliers and pinch off the inlet hose between the fuel filter and the gauge, also pinch the outlet hose between the fuel pressure regulator and the hard line returning to the fuel tank.
E. Monitor the fuel pressure gauge every 5 minutes.




F. Compare the time and amount of fuel pressure drop to chart 1.

Note:
An initial rise in pressure of 2-5 PSI is normal on a cold engine. A warm engine will have a larger rise in pressure.

Note:
If there is an actual leaking injector(s), the fuel pressure will fall to 0 PSI within about 10 minutes. The time will depend on the severity of the leak or the number of injectors leaking.

NO LEAKING INJECTOR FOUND: CONTINUE TO STEP 5

INJECTOR DETERMINED TO BE LEAKING: AFTER REPLACING THE LEAKING INJECTOR(S) CONTINUE TO CHECK FOR SENSORS THAT CAN CAUSE A RICH CONDITION. REPLACE THE ENGINE OIL AND ENGINE OIL FILTER BECAUSE OF FUEL IN THE OIL.