Removal Procedure

An 8-digit identification number is stamped on the fuel rail. Refer to this number if servicing or part replacement is required.

Fig 1: Removing Engine Fuel Feed Pipe From Fuel Rail
Courtesy of GENERAL MOTORS CORP.
1. Remove the engine fuel feed pipe from the fuel rail.
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.
NOTE: Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering the open pipes and passages.
2. Relieve fuel system pressure. Refer to Fuel Pressure Relief Procedure .
3. Remove the upper intake manifold. Refer to Intake Manifold Replacement - Upper in Engine Mechanical - 3.5L.
4. Disconnect the main injector harness electrical connector.
5. Disconnect the main fuel injector electrical harness connector.
Fig 2: Identifying Lock Release
Courtesy of GENERAL MOTORS CORP.
6. Pull up the lock release (2) of the fuel injector electrical connectors.
Fig 3: Disconnecting Fuel Injector Electrical Connectors
Courtesy of GENERAL MOTORS CORP.
7. Depress the lock tabs (1) and disconnect the fuel injector electrical connectors.
8. Remove the fuel injector electrical wiring harness from the fuel rail.
Fig 4: Fuel Rail Assembly
Courtesy of GENERAL MOTORS CORP.
9. Remove the fuel rail bolts.
10. Remove the fuel rail assembly.
11. Remove the fuel injector O-ring seal from the spray tip end of each injector.
12. Remove and discard O-rings if damaged.