Pontiac Fiero 1984-1988 Repair Guide

Intake Manifold

Print

REMOVAL & INSTALLATION



4-2.5L Engine


Click image to see an enlarged view

Fig. Fig. 1 Intake manifold location and components-four-cylinder engines



Click image to see an enlarged view

Fig. Fig. 2 Intake manifold torque sequence-2.5L engines


CAUTION
To reduce the risk of fire and personal injury, it is necessary to relieve the fuel system pressure before servicing any fuel system component. If this procedure is not performed, fuel may be sprayed out of the connection under pressure. Always keep a dry chemical (Class B) fire extinguisher near the work area.

  1. Fuel pressure relief procedures: remove the Fuel pump fuse from the fuse block located in the passenger compartment. Start the engine and run until the engine stops due to the lack of fuel. Crank the engine for 3 seconds to ensure all pressure is relieved.
  2.  
  3. Disconnect the negative (-) battery cable.
  4.  
  5. Remove the air cleaner assembly.
  6.  
  7. Remove the PCV valve and hose.
  8.  
  9. Drain the cooling system at the radiator.
  10.  


CAUTION
When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

  1. Disconnect the fuel lines at the intake manifold.
  2.  
  3. Disconnect the vacuum hoses.
  4.  
  5. Disconnect the wiring and the throttle linkage from the throttle body assembly.
  6.  
  7. Disconnect the cruise control linkage, if so equipped.
  8.  
  9. Disconnect the throttle linkage and bell crank and place to one side.
  10.  
  11. Disconnect the heater hose.
  12.  
  13. Remove the alternator upper bracket.
  14.  
  15. Remove the ignition coil, on vehicles with the separately mounted coil.
  16.  
  17. Remove the retaining bolts and remove the manifolds by tapping with a rubber hose.
  18.  

To install:

  1. Clean the mating surfaces on the manifold and cylinder head with a gasket scraper and solvent.
  2.  
  3. Install the manifold with a new gasket onto the cylinder head and install the seven retaining bolts hand-tight.
  4.  
  5. Important: refer to the Torque Specifications chart in the beginning of this section for the proper torque specifications for the year of the vehicle.
  6.  
  7. Install the heater hose and clamps, throttle linkage and bell crank and cruise control linkage.
  8.  
  9. Install the wiring and throttle linkage to the throttle body.
  10.  
  11. Install the vacuum hoses, fuel lines, PCV valve and refill with the proper engine coolant.
  12.  
  13. Install the air cleaner assembly and connect the negative (-) battery cable.
  14.  

2.8L V6 Engine


Click image to see an enlarged view

Fig. Fig. 3 Exploded view of the intake manifold assembly and tightening sequence-2.8L engine



Click image to see an enlarged view

Fig. Fig. 4 Tag the spark plug wires and mark their position on the distributor cap ...



Click image to see an enlarged view

Fig. Fig. 5 ... then disengage the spark plug wires



Click image to see an enlarged view

Fig. Fig. 6 Tag and disengage any vacuum hoses from the upper intake manifold



Click image to see an enlarged view

Fig. Fig. 7 Disconnect the hoses and fuel lines



Click image to see an enlarged view

Fig. Fig. 8 Loosen the inlet air tube clamp and then ...



Click image to see an enlarged view

Fig. Fig. 9 ... remove the inlet air tube from the throttle body assembly



Click image to see an enlarged view

Fig. Fig. 10 Remove the throttle linkage retaining clips . .



Click image to see an enlarged view

Fig. Fig. 11 ... then disconnect the linkage from the throttle body assembly



Click image to see an enlarged view

Fig. Fig. 12 Disconnect the MAP sensor and all other electrical connections from the upper intake manifold



Click image to see an enlarged view

Fig. Fig. 13 Use a ratchet and socket to remove the upper intake manifold retaining bolts ...



Click image to see an enlarged view

Fig. Fig. 14 ... then remove the upper intake manifold from the vehicle



Click image to see an enlarged view

Fig. Fig. 15 Unfasten its bolts and remove the intermediate intake manifold from the engine



Click image to see an enlarged view

Fig. Fig. 16 Remove the lower intake manifold bolts ...



Click image to see an enlarged view

Fig. Fig. 17 ... then remove the lower intake manifold from the vehicle


CAUTION
To reduce the risk of fire and personal injury, it is necessary to relieve the fuel system pressure before servicing any fuel system component. If this procedure is not performed, fuel may be sprayed out of the connection under pressure. Always keep a dry chemical (Class B) fire extinguisher near the work area.

  1. Disconnect the negative battery cable.
  2.  
  3. Fuel pressure relief procedures: remove the Fuel pump fuse from the fuse block located in the passenger compartment. Start the engine and run until the engine stops due to the lack of fuel. Crank the engine for 3 seconds to ensure all pressure is relieved.
  4.  
  5. Remove all non engine mounting vacuum lines.
  6.  
  7. Remove the throttle cable bracket bolts, throttle body bolts and plenum bolts.
  8.  
  9. Remove the upper plenum and gaskets by gently pulling upward or tapping with a rubber hammer if will not come loose.
  10.  
  11. Remove both rocker arm covers. Refer to the "Rocker Arm Cover" removal and installation procedures in this section.
  12.  
  13. Drain the engine coolant into a suitable drain pan at the radiator.
  14.  


CAUTION
When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

  1. Remove the distributor cap and move aside. Mark the position of the distributor rotor to the distributor housing and the housing to the engine. Remove the distributor assembly.
  2.  
  3. Disconnect the shift, cruise control and throttle linkage.
  4.  
  5. Remove the throttle body-to-upper plenum connector.
  6.  
  7. Disconnect the heater and radiator hoses.
  8.  
  9. Remove the radiator fill inlet.
  10.  
  11. Disconnect all wiring harness and vacuum hoses while noting their locations for reassembly.
  12.  
  13. Disconnect the vacuum booster pipe and bracket.
  14.  
  15. Disconnect the EGR pipe.
  16.  
  17. Remove the intermediate intake manifold and gasket.
  18.  
  19. Remove the lower intake manifold and gaskets.
  20.  

To install:

  1. Clean all gasket surfaces on the intake manifolds and cylinder head.
  2.  
  3. Install the lower intake manifold and gasket and torque in sequence to 19 ft. lbs. (26 Nm).
  4.  
  5. Install both rocker arm covers as outlined in the Rocker Arm Cover removal and installation procedures in this section. Torque the bolts to 90 inch. lb. (10 Nm).
  6.  
  7. Install the intermediate intake manifold and gaskets and torque in sequence to 15 ft. lbs. (21 Nm).
  8.  
  9. Install the upper manifold plenum and gaskets and torque in sequence to 18 ft. lbs. (25 Nm).
  10.  
  11. Install the EGR pipe, brake booster pipe and bracket, vacuum hoses, heater hoses, and wiring harness.
  12.  
  13. Install the inlet and return heater hoses and pipe to throttle body. Install the radiator fill inlet and radiator hose.
  14.  
  15. Install the throttle body to upper plenum and torque the bolts to 12.5 ft. lbs. (17 Nm).
  16.  
  17. Install the throttle, downshift and cruise control (if equipped) cables.
  18.  
  19. Install the distributor assembly into the same position as marked upon removal. Install the distributor cap and lock the four retaining clips.
  20.  
  21. Refill the radiator with the specified engine coolant.
  22.  
  23. Connect the negative (-) battery cable.
  24.  
  25. Start the engine and check engine timing with a inductive timing light.
  26.  
  27. Check for coolant, fuel and vacuum leaks.
  28.  

 
label.common.footer.alt.autozoneLogo