Fuel Injector: Service and Repair

Injector Replacement

WARNING: Compressed natural gas is flammable and highly explosive. You could be killed or seriously injured if leaking natural gas is ignited.
Stop the engine, and keep heat, sparks and flames away.

Removal

1. Relieve fuel pressure between the engine and manual shut-off valve.
2. Remove the air cleaner.




3. Disconnect the fuel pressure sensor 3P connector (A).
4. Disconnect the fuel pipe (8) from the fuel pressure regulator P2 (C) and fuel rail (D).
5. Disconnect the connectors from the injectors (E), the manifold absolute pressure (MAP) sensor (F), the throttle position (TP) sensor (G), and the fuel temperature sensor (H).
6. Remove the fuel rail mounting nuts (I) from the fuel rail
7. Remove the injectors from the fuel rail.
8. Remove the injector covers (J), cushion ring (K), seal ring (L), O-ring (M).

Installation




1. Install the injector covers (A)
2. Slide new cushion rings (B) onto the injectors (C).
3. Coat new O-rings (D) with silicone oil or polyalkyleneglycol (PAG) oil, and pull them on the injectors.
4. Insert the injectors into the fuel rail (F).
5. Coat new seal rings (F) with silicone oil or PAG oil, and press them into the injector base.
6. Install the injectors in the injector base.
7. Install and tighten the fuel rail mounting nuts.
8. Connect the connectors to the injectors, the MAP sensor, the TP sensor, and the fuel temperature sensor.
9. Connect the fuel pipe to the fuel pressure regulator and fuel rail.
10. Install the air cleaner
11. Perform the leak inspection procedure.