Fuel Rail: Service and Repair

Fuel Rail Assembly Identification:

NOTE: An eight digit identification number is stamped on the left hand fuel rail (fueling even numbered cylinders 2, 4, 6). Refer to this number if servicing or part replacement is required.

CAUTION: When servicing the fuel rail assembly, be careful to prevent dirt and other contaminants from entering open lines and passages. Fittings should be capped, and holes should be plugged, during servicing.
^ Any time the fuel system is opened for service, the O-rings should be replaced.
^ Before removal, the fuel rail assembly may be cleaned with a spray type engine cleaner, GM X30-A or equivalent, following package instructions. DO NOT soak the fuel rails in liquid cleaning solvent.

Air Plenum And Fuel Rail Removal:

REMOVAL:

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure, see MAINTENANCE PROCEDURES/FUEL SYSTEM PRESSURE RELIEF.
3. Remove the intake manifold plenum, see INTAKE MANIFOLD PLENUM.
4. Remove the fuel line bracket bolt.
5. Remove the fuel lines at the fuel rail. Use a back-up wrench on the fuel fittings to prevent them from turning.
6. Remove the fuel inlet and return line O-rings and discard.
7. Disconnect the vacuum line at the pressure regulator.
8. Remove the fuel rail retaining bolts.

CAUTION: Use care in removing the fuel rail assembly, to prevent damage to the injector spray tips, and the injector electrical connector terminals. When removed, support the rail to prevent damage to its components. The fuel injector is serviced as a complete assembly only. Since it is an electrical component, it should not be immersed in any liquid cleaner.

9. Remove the injector O-ring from the tip of each injector, and discard.

INSTALLATION:

1. Lubricate the O-ring seals with clean engine oil, and install one on the tip of each injector.
2. Install the fuel rail assembly in the intake manifold. Tilt the fuel rail assembly in the intake manifold. Tilt rail to install the injectors.
3. Install the fuel rail mounting bolts, and tighten to 10 Nm (88 lb.in).
4. Connect the fuel injector electrical connectors.
5. Put new O-rings on the fuel lines.
6. Attach the fuel feed and return line and tighten to 23 Nm (17 lb.ft). Use a back-up wrench on the fuel fittings to prevent them from turning.
7. Check for fuel leaks:
a. Temporarily connect the negative battery cable.
b. With the engine OFF and the ignition ON, check for fuel leaks.
c. Disconnect the negative battery cable.
8. Install the intake manifold plenum.
9. Connect the negative battery cable.



IDLE LEARN PROCEDURE: Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure:

1. After restoring battery power, connect the Tech 1 "Scan" tool.
2. Select "IAC System," then select "Idle Learn" in the "Misc. Test" mode.
3. Proceed with idle learn as directed.
^ This procedure allows the ECM memory to be updated with the correct IAC valve pintle position, for the vehicle, and provide a stable idle speed.