FD1 Check Fuel Injection Function

^ With the engine warmed and idling (or cranking if it does not start) and using a mechanic's stethoscope or equivalent, listen for regularly operating sounds at each fuel injector.

^ Is operating sound present?

YES -- GO to FD4. FD4 Check Fuel Injectors (Cleaning and Leakage)

NO -- GO to FD2. FD2 Check Fuel Injector Resistance