Important: You do not have to remove the upper intake manifold in order to remove the lower intake manifold.

1. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim.
2. Remove the air cleaner outlet duct from the throttle body. Refer to Air Cleaner Outlet Resonator Replacement in Engine Controls-4.3 L.
3. Remove the throttle body assembly. Refer to Throttle Body Assembly Replacement in Engine Controls - 4.3L.
4. Disconnect the accelerator control cable from the throttle shaft and the accelerator control cable bracket. Refer to Accelerator Control Cable Replacement in Engine Controls-4.3 L.
5. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator control cable bracket. Refer to Cruise Control Cable Replacement in Cruise Control.



6. Remove the PCV valve hose assembly from the intake manifold and the valve rocker arm cover.
7. Remove the nut holding the engine wiring harness bracket to the intake manifold stud.
8. Remove the engine wiring harness bracket from the stud.



9. Disconnect the following electrical connectors:

•	The A/C compressor clutch, if equipped (1)

•	The A/C high pressure cutoff switch, if equipped (5)

•	The throttle position (TP) sensor (2)

•	The idle air control (IAC) motor (3)

•	The fuel meter body assembly connector (4)




10. Disconnect the following electrical connectors:

•	The manifold absolute pressure (MAP) sensor (4)

•	The EVAP canister purge solenoid valve (1)




11. Remove the engine wiring harness bracket from the stud at the EVAP canister purge solenoid valve.
12. Move and secure the engine wiring harness out of the way.
13. Remove the EVAP canister purge valve to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls-4.3 L.



14. Disconnect the vacuum hose from the intake manifold.



15. Remove the bolt holding the transmission fluid filler tube to the accelerator control cable bracket.



16. Remove the accelerator control cable bracket from the throttle body and the intake manifold.
17. Remove the fuel lines from the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls-4.3 L.



18. Remove the studs for the upper intake manifold.
19. Remove the upper intake manifold.



20. Remove the upper intake manifold gasket from the groove.
21. Discard the gasket.



22. Remove the seal from the fuel meter body assembly.
23. Discard the seal.

Important: Do not immerse the assembled upper intake manifold in cleaning solvent.

24. Clean all sealing surfaces and the inside of the upper intake manifold with a shop towel and cleaning solvent.
25. Inspect the upper intake manifold for the following:

•	Cracks or other damage to the exterior

•	Cracking or damage to the gasket grooves

•	Loose or damaged bolt hole thread inserts




26. If replacing the upper intake manifold, turn and remove the PCV valve cover from the upper intake manifold.
27. Remove and discard the seal.
28. Remove the throttle body if replacing the upper intake manifold. Refer to Throttle Body Assembly Replacement in Engine Controls-4.3 L.
29. Remove the MAP sensor if replacing the upper intake manifold. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls-4.3 L.

1. Install the throttle body, if removed. Refer to Throttle Body Assembly Replacement in Engine Controls-4.3 L.
2. Install the MAP sensor, if removed. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls-4.3 L.
3. Install the PCV valve cover, if removed, using the following procedure:

3.1.	Install a NEW seal (O-ring) on the PCV valve cover.

3.2.	Lubricate the seal with clean engine oil.

3.3.	Install the PCV valve cover in the upper intake manifold.

3.4.	Turn and lock the PCV valve cover in position.




4. Install a NEW seal on the fuel meter body assembly.
5. Lubricate the seal with clean engine oil.



6. Install a NEW upper intake manifold to lower intake manifold gasket in the groove of the upper intake manifold.



7. Install the upper intake manifold onto the lower intake manifold.
8. If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the upper intake manifold attaching bolts.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

9. Install the upper intake manifold attaching studs.

Tighten

1. Tighten the upper intake manifold attaching studs on the first pass to 5 N·m (44 lb in).
2. Tighten the upper intake manifold attaching studs on the final pass to 9 N·m (80 lb in).
10. Install the fuel lines to the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls-4.3 L.
11. Install the EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls-4.3 L.



12. Install the accelerator control cable bracket, studs, and nuts to the intake manifold and the throttle body.

Tighten
Tighten the accelerator control cable bracket nuts and studs to 12 N·m (106 lb in).




13. Connect the vacuum hose to the intake manifold.



14. Install the transmission fluid fill tube and bolt to the accelerator control cable bracket.

Tighten
Tighten the transmission fluid fill tube bolt 6 N·m (53 lb in).




15. Position the engine wiring harness.
16. Connect the following electrical connectors:

•	The A/C compressor clutch, if equipped (1)

•	The A/C high pressure cutoff switch, if equipped (5)

•	The throttle position (TP) sensor (2)

•	The idle air control (IAC) motor (3)

•	The fuel meter body assembly connector (4)




17. Connect the following electrical connectors:

•	The manifold absolute pressure (MAP) sensor (4)

•	The EVAP canister purge solenoid valve (1)

18. Install the engine wiring harness bracket and nut to the intake manifold stud.

Tighten
Tighten the engine wiring harness bracket nut to 12 N·m (106 lb in).




19. Install the engine wiring harness bracket and the nut onto the stud at the EVAP canister purge solenoid valve.

Tighten
Tighten the engine wiring harness bracket nut to 8 N·m (71 lb in).




20. Connect the PCV valve hose assembly to the intake manifold and the valve rocker arm cover.
21. Install the cruise control cable, if equipped to the throttle shaft and the accelerator control cable bracket. Refer to Cruise Control Cable Replacement in Cruise Control.
22. Install the accelerator control cable to the throttle shaft and the accelerator control cable bracket. Refer to Accelerator Control Cable Replacement in Engine Controls-4.3 L.
23. Install the throttle body assembly. Refer to Throttle Body Assembly Replacement in Engine Controls - 4.3L.
24. Install the air cleaner outlet duct to the throttle body assembly. Refer to Air Cleaner Outlet Resonator Replacement in Engine Controls-4.3 L.
25. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim.