Fuel Injector: Service and Repair

***UPDATED BY TSB 91-312-6E DATED MAY 1991

The ball and seat design of the Multec port fuel injectors eliminates the need of ever having to use an injector cleaner. By design, the fuel metering portions of the fuel injector are not exposed directly to the intake manifold gases that are responsible for the build-up of deposits that can cause injector clog.

Some of these cleaners may contain high percentages of metnanol and other solvents that cause damage to the injectors coil wire insulation. Damaged insulation results in low resistance or shorted injectors. Also, high percentages of metnanol or other solvents can increase friction at the injectors critical bearing surfaces, resulting in premature wear.

Fuel Rail Assembly - Exploded View:

Fuel Rail Removal:

Intake Plenum Chamber:

REMOVAL:

CAUTION: Use care in removing injectors to prevent damage to the electrical connector pins on the injector and nozzle. The fuel injector is serviced as a complete assembly only. Since it is an electrical component, DO NOT immerse it in any type of cleaner.

1. Remove the negative battery cable.
2. Relieve the fuel system pressure, refer to MAINTENANCE PROCEDURES/FUEL SYSTEM PRESSURE RELIEF.
3. Remove the intake plenum assembly, refer to INTAKE MANIFOLD PLENUM.
4. Remove the fuel rail, refer to FUEL RAIL ASSEMBLY.
5. Remove the O-ring seals from the injectors and discard.

INSTALLATION:

Fuel Injector P/N Identification:

Fuel Injector Placement:

NOTE: Each injector is calibrated for a specific flow rate. When replacing fuel injectors, order replacements with the identical part numbers as the old injectors.

1. Lubricate new injector O-ring seals with clean engine oil and install on the injectors.
2. Install the injector retainer clips onto the injectors.
3. Install the injectors into the fuel rail injector sockets, with the electrical connector facing outward.
^ Push in far enough to engage the retainer clip with the machined slots on the rail socket.
4. Lubricate new injector housing O-ring seals with clean engine oil and install.
5. Install the fuel rail assembly into the injector housings.
6. Check for fuel leaks.
^ Temporarily connect the negative battery cable.
^ Turn the ignition switch to the ON position for two seconds, then turn it OFF for ten seconds. Again turn the ignition switch ON and check for fuel leaks.
^ Disconnect the negative battery cable.
7. Install the intake plenum assembly.
8. Tighten the fuel filler cap.
9. Connect the negative battery cable.