Caution: In order to reduce the risk of fire and personal injury that may result from a fuel leak, always install the fuel injector O-rings in the proper position. If the upper and lower O-rings are different colors (black and brown), be sure to install the black O-ring in the upper position and the brown O-ring in the lower position on the fuel injector. The O-rings are the same size but are made of different materials.

Important: When servicing the fuel rail assembly, precautions must be taken to prevent dirt and other contaminants from entering the fuel passages. It is recommended that the fittings be capped, and the holes be plugged during servicing.

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
2. Clean all fuel and evaporative emission (EVAP) pipe connections and surrounding areas before disconnecting in order to avoid possible contamination of the systems.
3. Disconnect the fuel feed pipe from the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .
4. Disconnect the EVAP pipe from the EVAP canister purge solenoid valve. Refer to Plastic Collar Quick Connect Fitting Service .
5. Remove the upper intake manifold. Refer to Upper Intake Manifold Installation .
6. Disconnect the engine harness electrical connector (2) from the fuel injector harness electrical connector (1).



7. Disconnect fuel injector harness electrical connector from the engine coolant temperature (ECT) sensor.



8. Disconnect the fuel injector harness electrical connector from the camshaft position (CMP) sensor.



9. Remove the fuel rail bolts.
10. Remove the fuel rail.
11. Remove the fuel injector O-ring seals from the spray tip end of each injector.
12. Remove the fuel injectors from the fuel rail, as necessary, refer to Fuel Injector Replacement .

Notice: 

Important: Install NEW lower O-ring seals when reusing the fuel injectors. Lubricate the injector tip O-rings prior to installing the injectors into the intake manifold.

1. Install the fuel injectors to the fuel rail, as necessary. refer to Fuel Injector Replacement .
2. Lubricate the fuel injector O-ring seal using GM P/N 12345616, (Canadian P/N 993182) or equivalent.
3. Place the fuel injectors into the injector bores.
4. Press on the fuel rail using the palms of both hands until the fuel injectors are fully seated.

Notice: Refer to Fastener Notice in the Preface section.

5. Install the fuel rail bolts.

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




6. Connect the fuel injector harness electrical connector to the CMP sensor.



7. Connect fuel injector harness electrical connector to the ECT sensor.



8. Connect the engine harness electrical connector (2) to the fuel injector harness electrical connector (1).
9. Install the upper intake manifold. Refer to Upper Intake Manifold Installation .
10. Connect the EVAP pipe to the EVAP canister purge solenoid valve. Refer to Plastic Collar Quick Connect Fitting Service .
11. Connect the fuel feed pipe to the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .
12. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
13. Inspect for fuel leaks.

13.1.

Turn ON the ignition for 2 seconds.

13.2.

Turn OFF the ignition for 10 seconds.

13.3.

Turn ON the ignition.

13.4.

Inspect for fuel leaks.