Tools Required

An 8-digit identification number is stamped 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. Relieve the fuel system pressure. Refer to the Fuel Pressure Relief .
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.

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.

4. Disconnect the fuel feed hose (2) from the fuel rail (1). Refer to Metal Collar Quick Connect Fitting Service .



5. Disconnect the accelerator cable from the throttle body and the accelerator cable bracket (without traction control).
6. Move the accelerator cable aside.



7. Disconnect the electrical connectors from the fuel injectors. Identify the connectors to their corresponding injectors to ensure correct sequential injector firing order after reassembly.
8. Disconnect the electrical harness from the fuel rail brackets.
9. Remove the fuel rail attaching bolts.
10. Remove the fuel rail assembly.
11. Remove the injector lower O-ring seal from the spray tip end of each injector.
12. Discard the O-ring seals.

1. Lubricate the new lower injector O-ring seals with clean engine oil.
2. Install the new O-ring seals on the spray tip end of each injector.
3. Install the fuel rail assembly to the intake manifold.
4. 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.

5. Install the fuel rail attaching bolts.

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

6. 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.

7. Connect the electrical harness to the fuel rail brackets.



8. Connect the accelerator cable to the throttle body and the accelerator cable bracket, if the vehicle does not have traction control.



9. Connect the fuel feed hose (2) to the fuel rail fuel pipe (1). Refer to Metal Collar Quick Connect Fitting Service .
10. Tighten the fuel filler cap.
11. Connect the negative battery cable.
12. Inspect for leaks.

12.1.

Turn ON the ignition for 2 seconds.

12.2.

Turn OFF the ignition for 10 seconds.

12.3.

Turn ON the ignition.

12.4.

Check for fuel leaks.

13. Perform the Idle Learn Procedure. Refer to Idle Learn .