Fuel Rail Assembly Replacement (With RPO Code KL8)

FUEL RAIL ASSEMBLY REPLACEMENT (With RPO Code KL8)

TOOLS REQUIRED
J 45878 Combustible Gas Detector

REMOVAL PROCEDURE
1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure.

CAUTION:
- Refer to Compressed Natural Gas (CNG) Flammability Caution in Service Precautions.
- Refer to Compressed Natural Gas (CNG) Fuel Pressure Relief Caution in Service Precautions.

2. Disconnect the negative battery cable.

CAUTION: Refer to Battery Disconnect Caution in Service Precautions.

3. Before removal, clean the fuel rail assembly with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.




4. Remove the engine sight shield.




5. Loosen and remove the fuel line to rail clamps (9).
6. Remove the fuel line retainers (7).
7. Disconnect the fuel lines (5, 8) from the fuel rails (1, 10).




8. Disconnect the fuel rail temperature and pressure sensor electrical connectors (7, 2).
9. Disconnect the 8 fuel injector electrical connectors (6).

IMPORTANT: Identify the injector connectors to their corresponding engine cylinder to ensure correct sequential injector firing order after reassembly.

10. Remove the fuel rail attaching bolts (1).
11. Remove the fuel rail with injectors as an assembly.

DISASSEMBLY PROCEDURE




1. Remove the injector (5) hold down clip.
2. Remove the injector from the fuel rail with a pulling and twisting motion.
3. Repeat steps 1 and 2 for the remaining fuel injectors.




4. Remove the fuel rail pressure or temperature sensor hold down bolt (6).
5. Remove the sensor (2) from the fuel rail (4) with a pulling and twisting motion.
6. Remove and discard any remaining O-rings from the fuel rail.

ASSEMBLY PROCEDURE




1. Install the fuel rail pressure or temperature sensor (2) into the fuel rail (4) using new O-rings (3). Lubricate the new O-rings with petroleum jelly.

CAUTION: Refer to Compressed Natural Gas (CNG) O-Ring Caution in Service Precautions.

2. Install the fuel rail pressure or temperature sensor hold down (5) and bolt (6).

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten the bolt to 3.8 N.m (34 lb in).




3. Install the fuel injector (5) into the fuel rail (3, 4) using a new O-ring. Lubricate the new O-ring with petroleum jelly.
4. Install the fuel injector retainer clip.
5. Lubricate the new injector tip O-ring with clean engine oil.
6. Repeat steps 3, 4 and 5 for the remaining fuel injectors.

INSTALLATION PROCEDURE




1. Install the fuel rails (3, 4) into the intake manifold.
2. Apply a 5 mm (0.020 in) band of GM P/N 1234382 threadlock, or equivalent, to the threads of the fuel rail attaching bolts.
3. Install the fuel rail attaching bolts (1).

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten the bolts to 10 N.m (89 lb in).

4. Connect the fuel injector electrical connectors (6) to the corresponding engine cylinder injector.
5. Connect the fuel rail pressure and temperature sensor electrical connectors (2, 7).




6. Install the fuel lines (5, 8) into the fuel rails (1, 10) using new O-rings. Lubricate the O-rings with petroleum jelly.
7. Install the fuel line to rail retainers (7) and clamps (9).

Tighten the clamps to 2 N.m (18 lb in).

8. Install the negative battery cable.

CAUTION: Refer to Battery Disconnect Caution in Service Precautions.

9. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings using the J 45878 or an equivalent liquid leak detector.




10. Install the engine sight shield (2).