Acura Coupes and Sedans 1994-2000 Repair Information

Intake Manifold

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REMOVAL & INSTALLATION



The radio may have a coded theft protection circuit. Make sure you have the code before disconnecting the battery, removing the radio fuse, or removing the radio.

1.8L (B18B1, B18C1 and B18C5) Engines See Figures 1, 2 and 3

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Fig. Fig. 1: As shown, space may be limited when trying to get to the bolts on the under side of the intake manifold.



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Fig. Fig. 2: Remove all of the intake manifold bolts as shown



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Fig. Fig. 3: There may be bolts hidden on the under side of the manifold

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system into a sealable container.
  4.  
  5. If equipped, remove the strut brace.
  6.  
  7. Remove the air intake duct.
  8.  
  9. Properly relieve the fuel pressure, as outlined in Fuel System .
  10.  
  11. Disconnect the fuel feed hose.
  12.  
  13. Remove the breather hose, the water bypass hose and the control canister hose from the throttle body.
  14.  
  15. Remove the fuel return hose.
  16.  
  17. Disconnect the Positive Crankcase Ventilation (PCV) hose.
  18.  
  19. Remove the brake booster vacuum hose, the water bypass hose and the vacuum hose from the manifold.
  20.  
  21. Remove the throttle cable from the throttle body. Take great care not to kink or damage the cable.
  22.  
  23. If necessary, remove the throttle body.
  24.  
  25. Label and disconnect all the emission vacuum hoses from the intake manifold.
  26.  
  27. Label and detach the wiring connected to the intake manifold. Disconnect sensors as needed; release wiring retainers and clips.
  28.  
  29. Disconnect the water bypass hoses from the manifold.
  30.  
  31. Remove the bolts attaching the intake manifold to the support bracket.
  32.  
  33. Remove the nuts attaching the intake manifold to the cylinder head. Remove the nuts in a crisscross pattern, beginning from the center and moving out to both ends.
  34.  
  35. Remove the manifold and the old gasket.
  36.  
  37. Clean the intake manifold mating surfaces. Inspect the manifold for cracks, flatness and/or damage; replace the parts, if necessary. If the intake manifold is to be replaced, transfer all the necessary components to the new manifold. On B18C1, B18C5 engines, the intake manifold may be removed from the air bypass valve body. If the manifold is removed, always install a new gasket before reassembly.
  38.  

To install:
  1. If the manifold was removed from the air bypass valve body, reassemble the components before installation. Tighten the through bolts to 17 ft. lbs. (24 Nm).
  2.  
  3. Use new gaskets when installing the intake manifold. Tighten the nuts, in a crisscross pattern, in 2-3 steps, starting with the inner nuts, to 17 ft. lbs. (23 Nm).
  4.  
  5. Install the bolts to the manifold support bracket. Tighten the bolts to 17 ft. lbs. (24 Nm).
  6.  
  7. The remainder of the procedure is the reverse of the removal. When connecting the fuel feed hose to the filter, use new washers and tighten the banjo bolt to 25 ft. lbs. (33 Nm) and the service bolt to 11 ft. lbs. (15 Nm). If applicable, when installing the strut brace, tighten the attaching nuts to 17 ft. lbs. (24 Nm). If removed, use a new gasket when installing the throttle body and tighten the nuts to 14 ft. lbs. (20 Nm).
  8.  
  9. After all removed components and connections have been reinstalled, refill and bleed the air from the cooling system.
  10.  
  11. Connect the negative battery cable and enter the radio security code. Start the engine and allow it to reach normal operating temperature.
  12.  
  13. Check for leaks and proper engine operation. Top off the engine coolant as necessary.
  14.  

2.2L, 2.3L Engines See Figure 4

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Fig. Fig. 4: Intake manifold and related components-2.3L engine

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine coolant into a sealable container.
  4.  
  5. Disconnect the cooling hoses from the intake manifold.
  6.  
  7. Label and unplug the vacuum hoses and electrical connectors on the manifold and throttle body. Unplug the connector from the Exhaust Gas Recirculation (EGR) valve. Position the wiring harnesses out of the way.
  8.  
  9. Disconnect the throttle cable from the throttle body.
  10.  
  11. Properly relieve the fuel pressure, as outlined in Fuel System .
  12.  
  13. Remove the fuel rail and fuel injectors.
  14.  
  15. Remove the thermostat housing mounting bolts. Remove the thermostat housing from the intake manifold and the connecting pipe, by pulling and twisting the housing. Discard the O-rings.
  16.  
  17. It may be necessary to remove the upper intake manifold plenum and throttle body assembly in order to access the nuts securing the manifold to the head.
  18.  
  19. Remove the intake manifold support bracket bolts and the bracket. It may be necessary to access it from under the vehicle; raise and support the vehicle safely.
  20.  
  21. While supporting the intake manifold, remove the nuts attaching the intake manifold to the cylinder head, then remove the manifold. Remove the old gasket from the cylinder head.
  22.  
  23. Clean any old gasket material from the cylinder head and the intake manifold. check and clean the FIA chamber on the cylinder head.
  24.  

To install:
  1. Using a new gasket, place the manifold into position and support.
  2.  
  3. Install the support bracket to the manifold. Tighten the bolt holding the bracket 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).
  6.  
  7. Using a new gasket, install the upper intake manifold and throttle body assembly, if removed as a separate unit. Tighten the nuts and bolts holding the chamber to 16 ft. lbs. (22 Nm).
  8.  
  9. Install a new O-ring to the coolant connecting pipe, and to the thermostat housing. Install the housing to the coolant pipe and the intake manifold. Tighten the mounting bolts to 16 ft. lbs. (22 Nm).
  10.  
  11. Connect and adjust the throttle cable.
  12.  
  13. Install the fuel rail/injector assembly. Connect the fuel lines.
  14.  
  15. Properly position the wiring harnesses and attach the electrical connectors.
  16.  
  17. Connect the vacuum hoses.
  18.  
  19. Fill and bleed the air from the cooling system.
  20.  
  21. Connect the negative battery cable and enter the radio security code.
  22.  
  23. Start the engine, checking carefully for any leaks of fuel, coolant or vacuum. Check the manifold gasket areas carefully for any leakage of vacuum.
  24.  

2.5L Engine

  1. Disconnect the negative battery cable.
  2.  
  3. Properly relieve the fuel system pressure, by removing the fuel filler cap and loosening the service bolt on the fuel filter. Remove the banjo bolt to remove the fuel feed hose from the fuel filter. Remove the fuel return hose from the pressure regulator.
  4.  
  5. Remove the throttle cable by loosening the locknut, then slip the cable end out of the throttle bracket and throttle linkage. Take care not to bend the cable when removing it. Move the cable aside.
  6.  
  7. Remove the engine harness cover. Label and disconnect the vacuum hoses and all wiring from the intake manifold.
  8.  
  9. To avoid having to drain the cooling system, remove the fast idle valve and the Idle Air Control (IAC) valve without disconnecting the coolant hoses. Move these components out of the work area so that they will not be damaged.
  10.  
  11. Remove the Exhaust Gas Recirculation (EGR) pipe and the vacuum pipe.
  12.  
  13. Remove the fuel rail. Remove the fuel injectors from the manifold. Handle the injectors and fuel rail carefully to avoid damaging them or contaminating them with dirt.
  14.  
  15. Unbolt the top bolts on the intake manifold brackets.
  16.  
  17. Remove the nuts that secure the manifold to the head. Remove the intake manifold from the engine.
  18.  

To install:

Use new O-rings when installing the IAC and fast idle valves.

  1. Inspect the manifold and its components for any signs of damage.
  2.  
  3. Fit the manifold to the engine with a new gasket and tighten the nuts to 16 ft. lbs. (22 Nm). Tighten the manifold bracket bolts to 16 ft. lbs. (22 Nm).
  4.  
  5. Install the fuel injectors into the rail and install the assembly onto the manifold with new sealing rings and cushion rings to prevent noise and leakage.
  6.  
  7. Connect the fuel injector harnesses and install the harness cover.
  8.  
  9. Install the IAC, fast idle, EGR, and EVAP valves. Use new O-rings.
  10.  
  11. Connect the wiring, vacuum hoses, and fuel lines. Use new sealing washers when connecting the fuel lines.
  12.  
  13. Install the throttle cable into its bracket and linkage. The throttle cable deflection is the measured by pressing down on the cable between the rubber boot and the linkage. The deflection must be 0.39-0.47 in. (10-12mm). Adjust the throttle cable as required.
  14.  
  15. Verify that all wiring and vacuum hoses are installed correctly.
  16.  
  17. Connect the negative battery cable. Run the engine and check for leaks.
  18.  

3.2L and 3.5L Engines

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system into a suitable container.
  4.  
  5. Remove the air intake duct from the throttle body.
  6.  
  7. On GS models, remove the TCS control valve assembly and its brackets from the throttle body.
  8.  
  9. Properly relieve the fuel system pressure by loosening the service bolt on the fuel filter about 1 turn, then disconnect the fuel supply and return lines from the manifold.
  10.  
  11. Remove the engine harness covers, tag and disconnect the wiring harnesses from the fuel injectors.
  12.  
  13. Remove the vacuum pipe harness, air inlet pipe, and Exhaust Gas Recirculation (EGR) pipe.
  14.  
  15. Remove the pulsed air injection pipe and valve.
  16.  
  17. Remove the intake manifold nuts and bolts in a crisscross pattern, beginning from the center and moving out to both ends of the manifold.
  18.  
  19. Verify that all vacuum lines are disconnected and remove the intake manifold and throttle body as a unit.
  20.  
  21. Remove the water passage and clean the gasket mounting surfaces.
  22.  
  23. Inspect the manifold for cracks, flatness, or other damage; replace any damaged parts. If the intake manifold is to be replaced, transfer all the necessary components to the new manifold.
  24.  

To install:

Always use new gaskets and O-rings during installation.

  1. Install the water passage.
  2.  
  3. Install the intake manifold and tighten the nuts/bolts, in a crisscross pattern in 2-3 steps, starting with the inner nuts. Tighten the 8mm bolts to 16 ft. lbs. (22 Nm) and the 6mm bolts to 9 ft. lbs. (12 Nm).
  4.  
  5. Reconnect the vacuum lines and the air inlet, and the EGR pipes.
  6.  
  7. Reconnect the fuel supply and return lines to the manifold. Tighten the fuel system service bolt.
  8.  
  9. Reconnect all intake manifold wiring connectors.
  10.  
  11. Install the TCS control valve assembly and brackets.
  12.  
  13. Install the air duct to the throttle body. Refill the cooling system.
  14.  
  15. Reconnect the negative battery cable. Start the engine, allow it to reach normal operating temperature and check for leaks and proper engine operation.
  16.  

 
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