Variable Induction System: Service and Repair

Upper Intake Removal

Remove or Disconnect

Fuel Pressure Connection:

1. Negative battery cable
2. Plastic cover.
3. Wire harnesses, including:
- Throttle Position (TP) sensor
- Idle Air Control (IAC) motor.
- Manifold Absolute Pressure (MAP) sensor.
- Intake manifold tuning valve assembly.
4. Throttle and cruise cable from upper intake manifold
5. Ignition coil
6. Crankcase ventilation hose at upper intake manifold
7. Vacuum hoses at front and rear of upper intake manifold.
8. Air cleaner snorkel
9. Upper intake manifold bolts and studs.
- Mark the location of all studs for proper reassembly.
10. Upper intake manifold

Important
Do Not attempt to disassemble the CMFI assembly. it is serviceable as an assembly.

CAUTION: Refer to "Fuel Pressure Relief Procedure" before disconnecting fuel lines.

Remove or Disconnect
1. Remove injector wiring harness connector at CMFI assembly.
2. Fuel fitting clip and discard.
3. Fuel inlet and return tube and fitting assembly
- Discard O-ring seals
4. CMFI assembly
- Squeeze poppet nozzle locking tabs together while lifting nozzle out of casting socket
- After removing the six poppet nozzles. lift the CMFI assembly out of casting

Install or Connect

CAUTION: To reduce the risk of fire and personal injury, verify that the poppet nozzles are firmly seated and locked in their casting sockets. An unlocked poppet nozzle could work loose from its socket thus resulting in a fuel leak.

1. CMFI assembly.
- Align CMFI assembly grommet with the casting grommet slots and push down until it is seated in bottom guide hole.
- Push poppet nozzles into casting sockets

Inspect
Poppet nozzles must be firmly seated and locked in casting sockets. Refer to previous "CAUTION" statement.

2. Fuel inlet and return tube and fitting assembly
- New O-ring seals coated with clean engine oil.
3. New fuel fitting clip.

Important
Test for fuel leakage. Pressurize fuel system, verify no fuel leakage at inlet and return tube to CMFI unit.

Upper Intake Installation

Install or Connect

CMFI Assembly Parts Identification:

1. Upper intake manifold gasket with green sealing lines facing up.
2. Upper intake manifold.
- Use care not to pinch the injector wires between the upper and lower intake manifolds
3. Upper intake manifold bolts. Use the marks made at disassembly for proper stud location.

Tighten
- Bolts to 10 Nm (88 lb.in.) using the sequence shown in image.

Upper Intake Manifold 4.3W:

4. Crankcase ventilation hose to upper intake manifold.
5. Vacuum hoses to front and rear of upper intake manifold.
6. Throttle and cruise cable to upper intake manifold.
7. Ignition coil.
8. Air cleaner tube.
9. Wire harnesses, including:
- Throttle Position (TP) sensor
- Idle Air Control (IAC) motor.
- Manifold Absolute Pressure (MAP) sensor.
- Intake manifold tuning valve assembly.
10. Plastic cover.

Thread-Locking Material

Important
The hardware used to attach the Throttle Position (TP) sensor, Idle Air Control (IAC) valve, Intake Manifold Tuning Valve and MAP sensor, are coated with thread-locking adhesive. If any of 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 screw 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.