Fuel Injector: Service and Repair

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 methanol 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 methanol or other solvents can increase friction at the injectors critical bearing surfaces, resulting in premature wear.

Intake Plenum Chamber:

Fuel Rail Removal:

Fuel Rail Assembly - Exploded View:

REMOVAL:

CAUTION: Use care in removing injectors to prevent damage to nozzle or the electrical connector pins on the injector. 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 fuel system pressure, See Fuel System Pressure Relief.
3. Remove intake plenum assembly, Service and Repair
4. Remove fuel rail assembly.
5. remove injector retaining clips and remove injectors from fuel rail.

WARNING: Re-using old O-rings may result in fuel leaks and cause fire hazard. Replace with new seals before re-assembly.

INSTALLATION:

Fuel Injector P/N Identification:

Fuel Injector Placement:

Plenum Bolt Tightening Sequence:

NOTE: Injectors are calibrated for a specific flow rate for each application. 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 and tighten bolts to 26 Nm (20 ft.lbs) in the sequence shown in illustration.

NOTE: always use new gaskets when installing plenum.

8. Tighten the fuel filler cap.
9. Connect the negative battery cable.