Honda Accord/Prelude 1984-1995 Repair Guide

Intake Manifold

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REMOVAL & INSTALLATION




CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container.

Carbureted Models

See Figures 1, 2, 3, 4, 5, 6 and 7

  1. Position a clean drain pan under the radiator, remove the drain plug and drain the cooling system.
  2.  
  3. Remove the air cleaner and housing from the carburetor(s).
  4.  



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Fig. Fig. 1: To remove the air suction valve, first disconnect the pipe from the valve assembly ...

  1. Remove the air valve, the Exhaust Gas Recirculation (EGR) valve, the Air Suction (AS) valve and the air chamber (if equipped).
  2.  



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Fig. Fig. 2: ... then remove the retaining bolts and remove the assembly from the engine. The carburetor is removed for clarity



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Fig. Fig. 3: The EGR crossover pipe will have to be removed on some models as well

On some models, it may be necessary to remove the air suction pipe and EGR crossover pipe to remove the intake manifold.

  1. Label and unplug any electrical connectors from the carburetor(s) and intake manifold.
  2.  
  3. Disconnect the fuel line(s) from the carburetor. Disconnect the throttle cable from the carburetor.
  4.  
  5. Remove the carburetor(s) from the intake manifold.
  6.  



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Fig. Fig. 4: An extension is helpful for reaching some intake manifold nuts



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Fig. Fig. 5: Once everything is disconnected from the manifold, it can be removed from the engine



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Fig. Fig. 6: Intake manifold used on 1984-85 carbureted Accords



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Fig. Fig. 7: Carbureted Prelude intake and exhaust manifold components

  1. Remove the nuts/bolts securing the manifold to any support brackets. On some models, it may be necessary to remove these nuts/bolts from under the car; safely raise and support the vehicle.
  2.  
  3. Remove the intake manifold-to-cylinder head nuts (using a crisscross pattern), beginning from the center and moving out to both ends, then remove the manifold.
  4.  
  5. Using a putty knife or piece of stiff plastic, clean the gasket mounting surfaces on the head. Do not use razor scrapers; the machined surfaces may be damaged, resulting in a leak.
  6.  
  7. If the intake manifold is to be replaced, transfer all the necessary components to the new manifold.
  8.  

To install:
  1. Use new gaskets and position the gasket and manifold on the head. Hand-tighten the nuts snug. Starting with the inner or center nuts, tighten the nuts in a crisscross pattern to the correct torque. The tension must be even across the entire face of the manifold if leaks are to be prevented.Correct torque is:

    1984-89 Accord: 16 ft. lbs. (22 Nm)
     
    1984-87 Prelude: 23 ft. lbs. (32 Nm)
     
    1988-90 Prelude: 17 ft. lbs. (24 Nm)
     

  2.  

  1. If applicable, secure the manifold to the support brackets. Tighten the nuts/bolts to 16 ft. lbs. (22 Nm).
  2.  
  3. Install the carburetor(s), making sure the insulator or base gasket is not damaged and is properly seated.
  4.  
  5. Connect the fuel lines and the throttle cable. Adjust the cable if necessary.
  6.  

  1. Engage the electrical and vacuum connections to the carburetor and manifold.
  2.  
  3. Install the emissions and air-control equipment removed for access. Always use a new gasket for the EGR valve; use care when handling and installing the air control valve, chamber and piping.
  4.  
  5. Install the air cleaner and housing.
  6.  
  7. Refill the coolant.
  8.  
  9. Start the engine, checking carefully for any leaks of fuel, coolant or vacuum. Check the manifold gasket area carefully for any leakage of vacuum.
  10.  

Fuel Injected Models
EXCEPT ACCORD V-6

See Figures 8 and 9

  1. Position a clean catch pan under the radiator, remove the radiator drain plug and drain the cooling system to a level below the intake manifold. Disconnect the cooling hoses from the intake manifold.
  2.  
  3. Label and unplug the vacuum hoses and electrical connectors on the manifold and throttle body. Disconnect the cable(s) from the throttle body. Unplug the connector from the Exhaust Gas Recirculation (EGR) valve.
  4.  
  5. Relieve the fuel pressure using the correct procedure.
  6.  
  7. Remove the fuel rail/injector assembly.
  8.  
  9. If equipped, remove the EGR crossover pipe.
  10.  



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Fig. Fig. 8: Single stage intake manifold used on 1990-95 Accords and 1988-95 Preludes

  1. On some models, it may be necessary to remove the upper intake manifold plenum/throttle body assembly in order to access the nuts securing the manifold to the head. On dual stage intake models, remove the intake air bypass actuator first. Remove the nuts/bolts securing the plenum/throttle body assembly to the manifold, then remove it.
  2.  



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Fig. Fig. 9: A dual stage intake manifold is also used on some models

  1. Remove the intake manifold support bracket bolts and the bracket(s). It may be necessary to access these from under the car; raise and support the vehicle safely.
  2.  
  3. While supporting the intake manifold, remove the intake manifold-to-cylinder head nuts; remove the manifold and the gasket from the cylinder head.
  4.  
  5. Using a putty knife or similar tool, clean the gasket mounting surfaces. Using a straight edge, check the surfaces for warpage; replace any warped parts.
  6.  

If the cylinder head/manifold mating surface is warped, it must be machined or replaced.

To install:
  1. Using a new gasket, place the manifold into position and support it. Install the nuts snug on the studs.
  2.  
  3. Install the support bracket(s) below the manifold. Tighten the bolts holding the brackets to the manifold to 16 ft. lbs. (22 Nm).
  4.  
  5. Starting with the inner or center nuts, tighten the nuts in a crisscross pattern to the correct torque. The tension must be even across the entire face of the manifold if leaks are to be prevented. Correct torque is 16 ft. lbs. (22 Nm) for all models.
  6.  
  7. If applicable, install the EGR crossover pipe. Use new gaskets and tighten the nuts to 9 ft. lbs. (12 Nm).
  8.  
  9. Using a new gasket, install the plenum/throttle body assembly if it was removed as a separate unit. Tighten the nuts and bolts holding the chamber to 16 ft. lbs. (22 Nm).
  10.  
  11. Connect the throttle body cable(s).
  12.  
  13. Install the fuel rail/injector assembly. Connect the fuel lines. Always use new washers at the banjo fittings.
  14.  
  15. Engage the electrical and vacuum connections.
  16.  
  17. Double check all installation items, paying particular attention to loose hoses or hanging wires, untightened nuts, poor routing of hoses and wires (too tight or rubbing) and tools left in the work area.
  18.  
  19. Refill the engine coolant.
  20.  
  21. Start the engine, checking carefully for any leaks of fuel, coolant or vacuum. Check the manifold gasket areas carefully for any leakage of vacuum.
  22.  

ACCORD V-6

See Figure 10

  1. Disconnect the negative battery cable.
  2.  
  3. Position a clean catch pan under the radiator, remove the radiator drain plug and drain the cooling system to a level below the intake manifold.
  4.  
  5. Remove the air intake duct.
  6.  
  7. Remove the throttle cable and cruise control cable by loosening the locknut, then slip the cable end out of the accelerator linkage.
  8.  
  9. It may be necessary to remove the strut tower brace for ease of access. If so, detach the starter cable from the strut tower brace, then remove the brace.
  10.  
  11. Relieve the fuel pressure using the correct procedure.
  12.  
  13. Remove the feed hose from the fuel filter.
  14.  

  1. Remove the brake booster, evaporative canister, and fuel return hoses.
  2.  
  3. Remove the intake manifold cover. It is secured by a series of small bolts.
  4.  
  5. Label and disconnect all vacuum and water hoses from the intake manifold and throttle body. If necessary, remove the vacuum pipe assembly.
  6.  
  7. Label and unplug all electrical connections on the manifold and throttle body. Remove the harness covers from the intake manifold.
  8.  
  9. Remove the Exhaust Gas Recirculation (EGR) crossover pipe. Discard the gasket.
  10.  
  11. Remove the bolts/nuts securing the intake manifold to the engine. Make sure all vacuum and electrical connections are unplugged. Remove any other components which may interfere with intake manifold removal. Carefully lift the manifold from the engine. Discard the gaskets.
  12.  
  13. Using a putty knife or similar tool, clean the gasket mounting surfaces.
  14.  

To install:

Always use new O-rings and gaskets.

  1. Using new gaskets, place the manifold into position. Install the nuts/bolts until just snug.
  2.  
  3. Starting with the inner or center nuts, tighten the nuts in a crisscross pattern to the correct torque. The tension must be even across the entire face of the manifold if leaks are to be prevented. Correct torque is 16 ft. lbs. (22 Nm).
  4.  
  5. Install the EGR crossover pipe using a new gasket. Tighten the nuts (to the intake manifold) to 9 ft. lbs. (12 Nm) and the pipe (to the exhaust manifold) to 43 ft. lbs. (59 Nm).
  6.  
  7. Install the harness covers on the intake manifold. Tighten the bolts to 9 ft. lbs. (12 Nm).
  8.  
  9. If applicable, install the vacuum pipe assembly. Tighten the bolts to 9 ft. lbs. (12 Nm).
  10.  
  11. Engage all electrical and vacuum connections on the throttle body and manifold. Install the intake manifold cover. Tighten the bolts to 9 ft. lbs. (12 Nm).
  12.  
  13. Connect the brake booster, evaporative canister, and fuel return hoses.
  14.  



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Fig. Fig. 10: Intake manifold used on the Accord V-6

  1. Connect the feed hose to the fuel filter with new gaskets. Tighten the union bolt to 16 ft. lbs. (22 Nm) and the service (pressure release) bolt to 9 ft. lbs. (12 Nm).
  2.  
  3. If applicable, install the strut tower brace. Tighten the bolts to 16 ft. lbs. (22 Nm). Attach the starter cable.
  4.  
  5. Install the throttle and cruise control cables. Install the air intake duct.
  6.  
  7. Double check all installation items, paying particular attention to loose hoses or hanging wires, untightened nuts, poor routing of hoses and wires (too tight or rubbing) and tools left in the work area.
  8.  
  9. Refill the engine coolant. Connect the negative battery cable.
  10.  
  11. Start the engine, checking carefully for any leaks of fuel, coolant or vacuum. Check the manifold gasket areas carefully for any leakage of vacuum.
  12.  

 
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