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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> Engine Mechanical >> Mechanical >> Engine Mechanical - 4.3L (On-Vehicle) >> Repair Instructions >> Intake Manifold Replacement - Lower >> Removal Procedure

Removal Procedure

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

  1. Disconnect the negative battery cable. Refer to BATTERY NEGATIVE CABLE DISCONNECT/CONNECT PROCEDURE .
  2. Disconnect the breather tube at the air cleaner outlet duct.
    Fig 1: Breather Tube
    G01661029Courtesy of GENERAL MOTORS CORP.
  3. Remove the air cleaner outlet duct retaining wingnut.
    Fig 2: Air Cleaner Outlet Duct Retaining Wingnut
    G01661030Courtesy of GENERAL MOTORS CORP.
  4. Disconnect the IAT sensor harness connector.
    Fig 3: IAT Sensor Harness Connector
    G01661031Courtesy of GENERAL MOTORS CORP.
  5. Remove the air cleaner outlet duct from the throttle body.
    Fig 4: Air Cleaner Outlet Duct
    G01661032Courtesy of GENERAL MOTORS CORP.
  6. Disconnect the accelerator cable from the throttle body.
    Fig 5: Accelerator Cable At Throttle Body
    G01661033Courtesy of GENERAL MOTORS CORP.
  7. Remove the accelerator cable from the accelerator control cable bracket.
  8. Disconnect the cruise control cable, if equipped, from the throttle shaft and the accelerator cable bracket. Refer to CRUISE CONTROL CABLE REPLACEMENT (4.3L) or CRUISE CONTROL CABLE REPLACEMENT (2.2L) .
    Fig 6: Accelerator Cable At Accelerator Control Cable Bracket
    G01661034Courtesy of GENERAL MOTORS CORP.
  9. Disconnect the vacuum hose from the intake manifold, if equipped with A/C.
  10. Disconnect the power brake booster vacuum hose
    Fig 7: Vacuum Hose
    G01661035Courtesy of GENERAL MOTORS CORP.
  11. Drain the cooling system. Refer to DRAINING AND FILLING COOLING SYSTEM .
  12. Remove the radiator inlet hose at the water outlet. Refer to RADIATOR HOSE REPLACEMENT - INLET (2.2L) or RADIATOR HOSE REPLACEMENT - INLET (4.3L) .
  13. Remove the heater hose from the intake manifold.
  14. Remove the water pump inlet hose from the intake manifold.
    Fig 8: Water Pump Inlet Hose
    G01661036Courtesy of GENERAL MOTORS CORP.
  15. Disconnect the following electrical connectors:
    • The fuel meter body assembly (1)
    • The EVAP canister purge solenoid valve (2)
    • The manifold air pressure (MAP) sensor (3)
    Fig 9: Fuel Meter Body Assembly, EVAP Canister Purge Solenoid Valve & MAP Sensor Electrical Connectors
    G01661037Courtesy of GENERAL MOTORS CORP.
  16. Disconnect the following electrical connectors:
    • The exhaust gas recirculation (EGR) valve (3)
    • The ignition coil (2)
    • The ignition control module (ICM) (1)
    • The generator (4)
    Fig 10: EGR Valve, Ignition Coil, ICM & Generator Electrical Connectors
    G01661038Courtesy of GENERAL MOTORS CORP.
  17. Disconnect the following electrical connectors:
    • The idle air control (IAC) motor (3)
    • The throttle position (TP) sensor (2)
    • The A/C compressor cutoff switch, if equipped (5)
    • The A/C clutch switch, if equipped (1)
    • The engine coolant temperature (ECT) sensor (4)
  18. Remove the engine wiring harness clips from the brackets.
  19. Move the engine wiring harness aside.
    Fig 11: IAC Motor, TP Sensor, A/C Compressor Cutoff Switch, A/C Clutch Switch & ECT Sensor Connectors
    G01661039Courtesy of GENERAL MOTORS CORP.
  20. Remove the accelerator cable bracket from the throttle body and the intake manifold.
    Fig 12: Accelerator Cable Bracket
    G01661040Courtesy of GENERAL MOTORS CORP.
  21. Remove the accelerator and the cruise control cable bracket from the throttle bracket.

    Leave the accelerator and cruise control cables on the bracket.

    Fig 13: Accelerator & Cruise Control Cable Bracket
    G01661041Courtesy of GENERAL MOTORS CORP.
  22. Disconnect the PCV hose assembly from the intake manifold and the valve rocker arm cover.
  23. Remove the EVAP canister purge solenoid valve. Refer to EVAP CANISTER PURGE SOLENOID .
    Fig 14: PCV Hose Assembly
    G01661042Courtesy of GENERAL MOTORS CORP.
  24. Remove the spark plug wire harness retainer from the exhaust gas recirculation (EGR) valve inlet pipe.
  25. Remove the clamp bolt for the EGR valve inlet pipe.
  26. Remove the EGR valve inlet pipe from the intake and the exhaust manifolds.
  27. Remove the distributor. Refer to DISTRIBUTOR .
  28. Disconnect the fuel supply and return pipes at the rear of the intake manifold.
    Fig 15: EGR Valve Inlet Pipe & Bolt
    G01661043Courtesy of GENERAL MOTORS CORP.

    Important:  Do not discharge the refrigerant.

  29. Perform the following in order to remove the left front bolt for the intake manifold:
    1. 29.1. Remove the drive belt. Refer to Drive Belt Replacement .
    2. 29.2. Loosen the nut for the power steering pump rear bracket at the side of the engine.
    3. 29.3. Remove the secondary air injection (AIR) reactor pipe bracket nut from the power steering pump rear bracket front stud, if equipped.
    4. 29.4. Remove the nut for the power steering pump rear bracket at the front of the engine.
    5. 29.5. Remove the bolts and the nut for the power steering pump mounting bracket.
    6. 29.6. Leave the A/C compressor, if equipped, and the power steering pump on the power steering pump mounting bracket.
    7. 29.7. Slide the power steering pump bracket forward to access the bolt at the front of the intake manifold.
    Fig 16: Power Steering Pump Brackets, Power Steering Pump, A/C Compressor, Bolts & Nuts
    G01661044Courtesy of GENERAL MOTORS CORP.
  30. Remove the engine coolant temperature (ECT) sensor wire connector (if equipped) from the engine wiring harness bracket.
  31. Remove the lower intake manifold bolts.

    Important:  The intake manifold may be removed as an assembly. Do not remove the specific intake manifold components unless component service is required.

    Do not allow dirt or debris to enter the fuel system. Ensure that the ends of the fuel system are properly sealed.

    Do not disassemble the Central Sequential Fuel Injection (SFI) unit, unless service is required.

  32. Remove the intake manifold assembly.
  33. Remove and discard the lower intake manifold gaskets.
    Fig 17: Intake Manifold Assembly & Gasket
    G01661045Courtesy of GENERAL MOTORS CORP.

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

  34. Clean the lower intake manifold in cleaning solvent.
  35. Dry the lower intake manifold with compressed air.
    Fig 18: Lower Intake Manifold
    G01661046Courtesy of GENERAL MOTORS CORP.
  36. Inspect the lower intake manifold for the following:
    • Damage to the gasket sealing surfaces (1), (2) and (3)
    • Restricted exhaust gas recirculation (EGR) system passages (4)
    • Restricted cooling system passages (5)
    • Cracks or damage
    • Damage to the threaded bolt holes
  37. If the intake manifold requires replacement Refer to INTAKE MANIFOLD DISASSEMBLE (L35) or INTAKE MANIFOLD DISASSEMBLE (LU3) and INTAKE MANIFOLD ASSEMBLE (L35) or INTAKE MANIFOLD ASSEMBLE (LU3) .
    Fig 19: Inspecting Lower Intake Manifold
    G01661047Courtesy of GENERAL MOTORS CORP.
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