An eight digit identification number (1) is located on the fuel rail assembly. Refer to this model identification number if servicing or part replacement is required.

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Remove the engine sight shield.
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 bracket bolts and bracket.



5. Disconnect the accelerator control cable and the cruise control cable from the cable bracket.



6. Disconnect the accelerator control cable and the cruise control cable from the throttle body.



7. Remove the upper engine wire harness retainer nut.
8. Disconnect the evaporative emission (EVAP) purge solenoid electrical connector.
9. Reposition the upper engine wire harness aside.
10. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .



11. Identify the connectors to their corresponding injectors to ensure correct sequential injector firing order after reassembly.
12. Pull the top portion (2) of the injector connector up. Do not pull the top portion of the connector past the top of the white portion (1).



13. Push the tab (1) on the lower side of the injector connector in order to release the connector from the injector.
14. Repeat step 12 and step 13 for each injector connector.




Notice: 

•	Remove the fuel rail assembly carefully in order to prevent damage to the injector electrical connector terminals and the injector spray tips. Support the fuel rail after the fuel rail is removed in order to avoid damaging the fuel rail components.

•	Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering open pipes and passages.

15. Disconnect the fuel feed and return pipes (1), (2) from the fuel rail.
16. Disconnect the fuel pressure regulator vacuum line.



17. Loosen the crossover tube to right fuel rail retainer screw (22).



18. Remove the fuel rail attaching bolts.
19. Remove the fuel rail assembly.



20. Remove the injector lower O-ring seal (4) from the spray tip end of each injector (3).
21. Discard the O-ring seals.

1. Lubricate the new lower injector O-ring seals (4) with clean engine oil.
2. Install the new O-ring seals (4) on the spray tip end of each injector (3).



3. Remove the crossover tube to the right fuel rail retainer (21).
4. Remove the crossover tube (25) from the right fuel rail (15).
5. Remove the O-ring (20) from the crossover tube (25).
6. Install a new O-ring on the crossover tube.
7. Lubricate the new O-ring with clean engine oil.
8. Install the crossover tube (25) into the right fuel rail (15).
9. Loosely install the crossover tube to the right fuel retainer (21).



10. Install the fuel rail assembly to the intake manifold.
11. Apply a 5 mm (0.020 in.) band of GM P/N 12345382 threadlock, or equivalent, to the threads of the fuel rail bolts.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

12. Install the fuel rail attaching bolts.

Tighten

1. Tighten the bolts to 10 N·m (89 lb in)
2. Tighten the right crossover pipe retainer screw to 3.8 N·m (34 lb in)



13. Connect the fuel pressure regulator vacuum line.
14. Connect the fuel feed and return pipes (1), (2) to the fuel rail.
15. Connect the injector electrical connectors.

•	Install each connector on the proper injector in order to ensure correct sequential injector firing order.

•	Rotate the injectors as required in order to avoid stretching the wire harness.




16. Position the upper engine wire harness in place.
17. Connect the EVAP purge solenoid connector.
18. Install the retainer nut to the upper engine wire harness.

Tighten
Tighten the nut to 5.5 N·m (49 lb in)




19. Connect the accelerator control cable and the cruise control cable to the cable bracket.



20. Connect the accelerator control cable and the cruise control cable to the throttle body.



21. Install the engine sight shield mounting bracket and the bolts.

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

22. Tighten the fuel filler cap.
23. Connect the negative battery cable.
24. Inspect for leaks.

24.1.

Turn the ignition ON for 2 seconds.

24.2.

Turn the ignition OFF for 10 seconds.

24.3.

Turn the ignition ON.

24.4.

Inspect for fuel leaks.

25. Install the engine sight shield.

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