Fuel Rail: Service and Repair

WARNING: To reduce the risk of fire and personal injury that may result from a fuel leak, always replace O-ring seals exposed during component service.

CAUTION: Use care in removing the fuel rail assembly, to prevent damage to the injector spray tips and to the injector electrical connector terminals. When removed, support the rail to avoid damaging its components.
^ Prevent dirt and other contaminates from entering open lines and passages. Fittings should be capped, and holes plugged, during servicing.

NOTE: Before removal, the fuel rail assembly may be cleaned with a spray type engine cleaner, GM X-30A or equivalent, following package instructions. Do not immerse the fuel rail in liquid cleaning solvent.
^ An eight digit identification number is stamped on the side of the fuel rail. Refer to this number if servicing or part replacement is required. The names of component parts appear in the numbered lists on the following exploded views.

Fuel Rail Assembly Identification:

Air Plenum/Fuel Rail Assembly Exploded View:

Fuel Rail Assembly Model R610:

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 cold start tube from the fuel rail fitting. Use a back-up wrench on the fuel rail fitting to prevent it from turning.
5. Remove the cold start tube O-ring seal, and discard.
6. Disconnect the fuel feed and return lines from the fuel rail.
7. Remove the fuel line O-rings, and discard.
8. Remove the vacuum line from the fuel pressure regulator.
9. Remove the injector electrical connectors.
10. Remove the fuel rail attaching bolts.
11. Carefully remove the fuel rail assembly.
12. Remove the O-ring seal from the spray tip end of each injector, discard seals.

INSTALLATION:

1. Lubricate the new injector O-ring seals with clean engine oil, and install them on the spray tip end of each injector.
2. Carefully position the fuel rail assembly into the intake manifold. Tilt the fuel rail assembly to install the injectors into the manifold.
3. Insert the fuel rail attaching bolts and torque to 25 Nm (18 lb.ft).
4. Reconnect the injector electrical connectors. Rotate the injectors as required to avoid stretching the wire harness.
5. Attach the vacuum line to the fuel pressure regulator.
6. Install new O-ring seals on the fuel feed and return lines.
7. Connect the fuel lines, and tighten to 27 Nm (20 lb.ft).
8. Install a new O-ring seal on the cold start tube.
9. Attach the cold start tube nut to the fitting on the fuel rail. Tighten the cold start tube nut to 27 Nm (20 lb.ft). Use a back-up wrench on the fuel rail fitting to prevent it from turning.
10. 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.
11. Install the intake manifold plenum.
12. Connect the negative battery cable.