Fuel Injector: Service and Repair
Upper And Lower Manifold Assemblies:
Upper And Lower Manifold Assembly-Part Name:
Injector Part Number Location:
WARNING: To reduce the chance of personal injury, cover regulator and fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container after disconnect is completed.
CAUTION: Always remove the fuel pressure regulator to drain excess fuel, and to prevent fuel from entering engine cylinders when injectors are removed for service. Flooded cylinders could result in engine damage.
CAUTION: Use care in removing injectors to prevent damage to the electrical connector pins on the injector and the nozzle. The fuel injector is serviced as a complete assembly only. Since it is an electrical component Do Not soak it in cleaner.
REMOVE OR DISCONNECT
1. Relieve fuel system pressure.
- Refer to the Fuel Pressure Relief Procedure. Service and Repair
2. Disconnect negative battery cable.
3. Upper manifold assembly.
- Refer to Upper Manifold Assembly. Service and Repair
4. Fuel return line retaining bracket nut.
5. Fuel return line retaining bracket.
- Move return line away from regulator.
6. Pressure regulator assembly.
- Refer to Fuel Pressure Regulator Assembly. Service and Repair
NOTE: To prevent damage to injector retaining bracket and/or injectors, do not try to remove injectors by lifting up the injector retaining bracket while injectors still are installed in bracket slots.
- Do Not attempt to remove bracket without first removing fuel pressure regulator.
7. Injector retainer bracket attaching screws.
8. Injector retainer bracket.
- Carefully slide bracket off to clear injector slots and regulator.
9. Electrical injector connector(s).
CAUTION: 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 leaks.
10. Fuel injector(s).
- Discard O-ring seals.
NOTE: Each injector is calibrated for a specific flow rate. When replacing fuel injectors, order replacements with the identical part number as the old injectors.
NOTE: Cover injector sockets to prevent dirt and other contaminants from from entering open fuel passages.
INSTALL OR CONNECT
1. Lubricate new injector O-ring seals with clean engine oil, and install on injector assembly.
- See "WARNING" statement above.
2. Bottom feed multiport injector assembly into lower manifold injector socket with electrical connectors facing inward.
3. Injector retainer bracket.
- Carefully install bracket so that injector retaining slots and regulator are aligned with bracket slots.
4. Electrical injector connectors.
5. Pressure regulator assembly.
- Refer to Pressure Regulator Assembly. Service and Repair
6. Injector retainer bracket attaching screws.
Thread-Locking Material.
The hardware used to attach the 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 insure 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.
7. Upper manifold assembly.
- Refer to Upper Manifold Assembly. Service and Repair
Tighten
- Injector retainer bracket attaching screws to 3.5 Nm (31 lb. in.).
8. Accelerator cable bracket with attaching bolts/nuts.
Tighten
- Accelerator cable bracket nut to 30 Nm (22 lb. ft.).
- Accelerator cable bracket bolts to 25 Nm (18 lb. ft.).
9. Tighten fuel filler cap.
10. Negative battery terminal.
INSPECT
- Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position and check for fuel leaks.
11. Air intake duct.