Fuel Injector: Service and Repair

** CONTAINS UPDATED INFORMATION PER TSB # 61-63-09 **

CAUTION: In order to prevent possible engine damage, these procedures must be followed:

- Extra attention must be take to ensure that all O-rings are installed properly on bottom feed fuel injectors prior to installation.
- Bottom feel fuel injectors must be installed carefully to prevent the O-rings from being damaged which can cause fuel to enter the engine cylinders.
- Following the replacement of bottom feed injectors, the System Diagnostic Table: Fuel System Diagnosis Test should be performed to verify that the bottom feed fuel injectors are not leaking.
Testing and Inspection
- If the fuel system does not hold pressure, the engine must not be cranked over. Diagnose the loss of fuel pressure before cranking the engine.

REMOVAL PROCEDURE
1. Perform the Fuel Pressure Release Procedure.
2. Disconnect the negative battery cable.
- Refer to Service Precautions.

WARNING:
- In order to reduce the risk of fire and personal injury, It Is necessary to relieve the fuel system pressure before servicing fuel system components.
- After relieving system pressure, a small amount of fuel may be released when servicing fuel pipes or connections. In order to reduce the chance of personal injury cover fuel pipe fittings with a shop towel before disconnecting the fuel pipes in order to catch any fuel that may leak out. Place the towel in an approved container when the disconnect is completed.

3. Remove the upper manifold assembly.
4. Remove the fuel return pipe retaining bracket nut (8).
5. Remove the fuel return pipe retaining bracket.
- Move the return pipe away from the regulator.

CAUTION:
- In order to prevent damage to the fuel injector retaining bracket and fuel injectors, do not try to remove the fuel injectors by lifting up the fuel injector retaining bracket while the fuel injector are still installed in the bracket slots.
- Do not attempt to remove the bracket without first removing the fuel pressure regulator.

6. Remove the pressure regulator assembly (6).
7. Remove the injector retainer bracket attaching screws (11).
8. Remove the injector retainer bracket (12). Carefully slide bracket off to clear fuel injector slots and regulator.

WARNING: In order to reduce the risk of fire and personal Injury, verify that the lower (small) O-Ring of each Injector does not remain in the lower manifold. If the O-Ring is not removed with the injector; the replacement Injector with new O-Rings, will not seat properly in the Injector socket and could cause a fuel leak.

9. Disconnect the injector electrical connector(s).
10. Remove the fuel injector(s) (5).
- Discard O-Ring seals (4).

INSTALLATION PROCEDURE
Each fuel injector is calibrated for a specific flow rate. When replacing fuel injectors, be sure to order the correct fuel injector for the application being serviced.

1. Lubricate new fuel injector O-Ring seals (4) with clean engine oil, and install on fuel injector assembly (5).
2. Install the bottom feed fuel injector assembly (5) into lower manifold fuel injector socket with the electrical connectors facing inward.
3. Install the injector retainer bracket (12). Carefully install the bracket so that fuel injector retaining slots and the regulator are aligned with the bracket slots.

4. Connect the injector electrical connectors.
5. Install the pressure regulator assembly (6).

6. Install the injector retainer bracket attaching screws (11). - Refer to Thread Locking Material.

Tighten
Screws to 3.5 Nm (31 lb in).

7. Install the upper manifold assembly.
8. Install the fuel return pipe retaining bracket.
9. Install the accelerator cable bracket with attaching bolts/nuts.

Tighten
Bracket nut to 30 Nm (22 lb ft).
Bracket bolts to 25 Nm (18 lb ft).

10. Tighten the fuel filler cap.
11. Connect the negative battery cable.
12. Install the air intake duct.
13. Inspect for leaks.
1. Turn the ignition switch ON for 2 seconds.
2. Turn the ignition switch OFF for 10 seconds.
3. Turn the ignition switch ON.
4. Check for fuel leaks.

NOTE: The hardware used to attach the pressure regulator and injector bracket attaching hardware are coated with thread-locking adhesive. If any these parts are removed for service, inspect the attaching screw threads. There should be enough thread-locking material (adhesive or compound) on the threads to ensure proper relocking. If not, clean the threads and apply Loctite 262, or equivalent, to the threads before reassembly. Replacement screws are included in the service screw assortment package. New attaching hardware is included in the service packages.