Acura Coupes and Sedans 1986-1993 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



1986-90 Integra

See Figures 1 and 2

Cylinder head temperature must be below 100°F.

Before removing the cylinder head check the following:



Inspect the timing belt.
 
Turn the flywheel so the No. 1 cylinder is at TDC.
 
Mark all connectors and vacuum hoses before disconnecting them.
 

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air cleaner:
    1. Remove the air cleaner cover and filter.
    2.  
    3. Disconnect the hot/cold air intake ducts and remove the air chamber hose.
    4.  
    5. Remove the air cleaner.
    6.  

  6.  
  7. Slowly loosen the service bolt on the top of the fuel filter about 1 turn to relieve the fuel system pressure. Disconnect the fuel return hose from the pressure regulator.
  8.  


CAUTION
The fuel system may be under pressure and fuel will be sprayed. Be sure there is good ventilation and take the appropriate fire safety precautions.

  1. Remove the brake booster vacuum tube from the intake manifold.
  2.  
  3. Remove the engine ground wire from the valve cover. Disconnect the throttle cable from the throttle body.
  4.  
  5. Disconnect the spark plug wires from the spark plugs and remove the distributor assembly.
  6.  
  7. Disconnect the hoses from the charcoal canister and from the No. 1 control box at the tubing manifold.
  8.  
  9. If equipped with air conditioning, disconnect the idle control solenoid hoses.
  10.  
  11. Disconnect the upper radiator heater and bypass hoses.
  12.  
  13. Disconnect the engine sub harness connectors and the following connectors from the cylinder head and the intake manifold:
    1. The 4 injector connectors.
    2.  
    3. The TA sensor connector.
    4.  
    5. The ground connector.
    6.  
    7. The TW sensor connector.
    8.  
    9. The throttle sensor connector.
    10.  
    11. The crankshaft angle sensor connector.
    12.  
    13. The EACV connector, if equipped.
    14.  
    15. The CYL sensor connector, if equipped.
    16.  

  14.  
  15. Remove the thermostat housing-to-intake manifold hose.
  16.  
  17. Unplug the oxygen sensor connector.
  18.  
  19. Remove the exhaust manifold bracket, the manifold bolts and the manifold.
  20.  
  21. Remove the bolts from the intake manifold and bracket.
  22.  
  23. Disconnect the breather chamber-to-intake manifold hose.
  24.  
  25. Remove the valve and upper timing belt covers.
  26.  
  27. Loosen the timing belt tensioner adjustment bolt and remove the belt.
  28.  
  29. Remove the lower timing belt cover bolts, the camshaft holder bolts, the camshaft holders, the camshafts and the rocker arms.
  30.  
  31. Remove the cylinder head bolts in the reverse order given in the head bolt torque sequence.
  32.  

Unscrew the bolts1/3of a turn each time and repeat the sequence to prevent cylinder head warpage.

  1. Carefully, remove the intake manifold from the cylinder head and the cylinder head from the engine.
  2.  
  3. Clean the gasket mounting surfaces.
  4.  



Click image to see an enlarged view

Fig. Fig. 1: Cylinder head and valve train-1986-90 Integra



Click image to see an enlarged view

Fig. Fig. 2: Cylinder head bolt torque sequence-1986-90 Integra

To install:
  1. Using new gaskets, install the intake manifold onto the cylinder head and torque the nuts to 23 ft. lbs. (32 Nm) in a crisscrosss pattern in 2-3 steps.
  2.  
  3. Install the cylinder head onto the engine block, after making sure the mating surface was cleaned and a new gasket was installed. Be sure to pay attention to the following points:
    1. Be sure the No. 1 cylinder is at TDC and the camshaft pulleys UP mark is on the top before positioning the head in place.
    2.  
    3. The cylinder head dowel pins and oil control jet must be aligned.
    4.  
    5. Torque the cylinder head bolts in 2 progressive steps and in the proper sequence. First to 22 ft. lbs. (30 Nm), in sequence, then to 48 ft. lbs. (67 Nm), in the same sequence.
    6.  
    7. Use the longer bolt in the No. 9 position.
    8.  

  4.  
  5. Make sure the keyways on the camshafts are facing up. The valve locknuts should be loosened and the adjusting screw backed off before installation. Replace the rocker arms in their original position.
  6.  
  7. Place the rocker arms on the pivot bolts and the valve stems.
  8.  
  9. Install the camshafts and the camshaft seals with the open side facing in.
  10.  
  11. Be sure to note the I and E marks that are stamped on the camshaft holders. Do not apply oil to the seal mating surface of the camshaft holders.
  12.  
  13. Apply a liquid gasket to the head of the mating surfaces of the No. 1 and No. 6 camshaft holders then install them, along with No. 2, 3, 4 and 5. Tighten each bolt 1 turn at a time to insure that the rockers do not bind on the valves.
  14.  
  15. Torque the camshaft holder bolts and make sure the rocker arms are properly positioned on the valve stems. Start at the center holders and work out towards the ends, torque the bolts to 9 ft. lbs. (12 Nm).
  16.  
  17. Press in the camshaft seal securely with a suitable seal driver.
  18.  
  19. Install the keys into their groves in the camshafts. To set the No. 1 piston at TDC, align the holes on the camshaft with the holes in the No. 1 camshaft holders and drive 5.0mm pin punches into the holes.
  20.  
  21. Push the camshaft pulleys onto the camshafts, then torque the retaining bolts to 27 ft. lbs. (38 Nm).
  22.  
  23. Install the timing belt and adjust the timing belt tension. Install the lower timing belt cover and bolts.
  24.  
  25. Install the upper timing belt covers and valve covers.
  26.  
  27. Reconnect the breather chamber-to-intake manifold hose.
  28.  
  29. Install the exhaust manifold, the manifold bolts and the manifold bracket.
  30.  
  31. Reconnect all disconnected electrical connections and vacuum lines.
  32.  
  33. Reconnect the upper radiator hose and bypass hoses.
  34.  
  35. Reinstall the distributor assembly and the spark plug wires to the spark plugs.
  36.  
  37. Install the engine ground wire from the valve cover. Reconnect the throttle cable from the throttle body.
  38.  
  39. Reinstall the air cleaner assembly and duct work that goes along with it. Reconnect the negative battery cable.
  40.  
  41. After installation, check to see that all hoses and wires are installed correctly.
  42.  
  43. Refill the coolant system.
  44.  
  45. Adjust the valve clearance. Make all other necessary adjustments
  46.  

It is recommended that after completing the cylinder head removal and installation, the engine oil should be changed.

1991-93 Integra

See Figures 3 through 8

Cylinder head temperature must be below 100°F.

Before removing the cylinder head check the following:



Inspect the timing belt.
 
Turn the flywheel so the No. 1 cylinder is at TDC.
 
Mark all emission hoses before disconnecting them.
 

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air cleaner:
    1. Remove the air cleaner cover and filter.
    2.  
    3. Disconnect the hot/cold air intake ducts and remove the air chamber hose.
    4.  
    5. Remove the air cleaner.
    6.  

  6.  
  7. Relieve the fuel pressure by slowly loosening the service bolt on the top of the fuel filter about a turn.
  8.  


CAUTION
The fuel system may be under pressure and fuel will be sprayed. Be sure to take the appropriate safety and fire precautions.

  1. Disconnect the fuel feed line. Remove the vacuum hose, breather hose and air intake hose.
  2.  
  3. Remove the water bypass hose from cylinder head. Remove the charcoal canister hose from the throttle body.
  4.  
  5. Remove the brake booster vacuum hose from the intake manifold. Remove the fuel return hose. Remove the PCV hose.
  6.  
  7. Remove the throttle cable from the throttle body. Take care not to bend the cable when removing it. Do not use pliers to remove the cable from the linkage. Always replaced a kinked cable with a new one.
  8.  
  9. Disconnect the ignition coil connector, TDC and crankshaft/cylinder sensor connector from the distributor.
  10.  
  11. Remove and tag the spark plug wirers.
  12.  
  13. Remove the emission control equipment bracket but do not disconnect the emission hoses.
  14.  
  15. Disconnect the 3 engine harness connectors on the left side of the engine compartment.
  16.  
  17. Disconnect the engine sub-harness connectors from the cylinder head and intake manifold. The connectors are as follows:
    1. Four injector connectors.
    2.  
    3. TA sensor connector.
    4.  
    5. Throttle angle sensor connector.
    6.  
    7. EGR valve lift sensor; automatic transaxle only.
    8.  
    9. Ground cable terminal.
    10.  
    11. TW sensor ground.
    12.  
    13. Coolant temperature gauge sender terminal.
    14.  
    15. Oxygen sensor terminal.
    16.  
    17. EACV connector.
    18.  

  18.  
  19. Remove the upper radiator hose and heater inlet hose from the cylinder head.
  20.  
  21. Remove the power steering belt and power steering pump. Do not disconnect the hoses from the pump.
  22.  
  23. Raise and safely support the vehicle.
  24.  
  25. Remove the left front wheel and then remove the left splash shield.
  26.  
  27. Remove the intake manifold bracket bolts and remove the exhaust manifold upper shroud.
  28.  
  29. Remove the exhaust manifold bracket. Remove front exhaust pipe and remove the exhaust manifold.
  30.  
  31. Remove the valve cover and engine ground cable.
  32.  
  33. Remove the timing belt middle cover. Loosen but do not remove the adjusting bolt and release the timing belt tension. Tighten the bolt to hold the tensioner in the released position.
  34.  
  35. Remove the timing belt from the driven pulleys. Be sure not to crimp or bend the timing belt more then 90 degrees in less then 1 in. (25mm) in diameter.
  36.  
  37. Remove the camshaft driven pulleys. Loosen all the camshaft holder bolts 1 full turn at a time to release valve spring pressure evenly. Remove the camshaft holder bolts, then remove the camshaft holders, camshafts and rocker arms.
  38.  



Click image to see an enlarged view

Fig. Fig. 3: Cylinder head and valve train-1991-93 Integra 1.8L



Click image to see an enlarged view

Fig. Fig. 4: Cylinder head bolt loosening sequence-1991-93 Integra 1.8L



Click image to see an enlarged view

Fig. Fig. 5: Cylinder head bolt torque sequence-1991-93 Integra 1.8L



Click image to see an enlarged view

Fig. Fig. 6: Cylinder head and valve train-1991-93 Integra 1.7L



Click image to see an enlarged view

Fig. Fig. 7: Cylinder head bolt loosening sequence-1991-93 Integra 1.7L



Click image to see an enlarged view

Fig. Fig. 8: Cylinder head bolt torque sequence-1991-93 Integra 1.7L

  1. Remove the cylinder head bolts and remove the cylinder head. To prevent warpage, unscrew all the cylinder head bolts in sequence 1 / 3 turn at a time, repeat this sequence until all the bolts are loosened.
  2.  
  3. Remove the intake manifold from the cylinder head.
  4.  

To install:
  1. Use new gaskets and install the intake manifold onto the cylinder head and tighten the nuts in a crisscrosss pattern in 2-3 steps, beginning in the middle. Torque the nuts to 17 ft. lbs. (23 Nm).
  2.  
  3. Install the cylinder head onto the engine block, after making sure the mating surface was cleaned and a new gasket was installed. Be sure to pay attention to the following points:
    1. Be sure the No. 1 cylinder is at TDC and the camshaft pulley UP mark is on the top before positioning the head in place.
    2.  
    3. The cylinder head dowel pins and oil control jet must be aligned.
    4.  
    5. Torque the cylinder head bolts, in 2 progressive steps: First to 22 ft. lbs. (30 Nm), in sequence, then to 61 ft. lbs. (85 Nm), in the same sequence. This sequence is the same as on earlier Integra engines.
    6.  
    7. Apply engine oil to the cylinder head bolts and washers. Use the longer bolt in the No. 1 and No. 2 positions.
    8.  

  4.  
  5. Make sure the keyways on the camshafts are facing up. The valve locknuts should be loosened and the adjusting screw backed off before installation. Replace the rocker arms in their original position.
  6.  
  7. Place the rocker arms on the pivot bolts and the valve stems.
  8.  
  9. Install the camshafts and the camshaft seals with the open spring side facing in.
  10.  
  11. Be sure to note the I and E marks that are stamped on the camshaft holders. Do not apply oil to the seal mating surface of the camshaft holders.
  12.  
  13. Apply a liquid gasket to the head of the mating surfaces of the No. 1 and No. 6 camshaft holders then install them, along with No. 2, 3, 4 and 5. Tighten each bolt 1 turn at a time to insure that the rockers do not bind on the valves.
  14.  
  15. Torque the camshaft holder bolts and make sure the rocker arms are properly positioned on the valve stems. Start at the center holders and work out towards the ends, torque the bolts to 9 ft. lbs. (12 Nm).
  16.  
  17. Press in the camshaft seal securely with a suitable seal driver.
  18.  
  19. Install the keys into their groves in the camshafts. To set the No. 1 piston at TDC, align the holes on the camshaft with the holes in the No. 1 camshaft holders and drive 5.0mm pin punches into the holes.
  20.  
  21. Push the camshaft pulleys onto the camshafts, then torque the retaining bolts to 27 ft. lbs. (38 Nm).
  22.  
  23. Install the timing belt and adjust the tension. Install the lower and middle timing belt covers and bolts.
  24.  
  25. Install the valve cover and engine ground cable.
  26.  
  27. Install the exhaust manifold and torque the nuts to 23 ft. lbs. (32 Nm). Install the bracket and upper shroud and attach the exhaust pipe.
  28.  
  29. Install the left front wheel splash shield and the left front wheel. Lower the vehicle.
  30.  
  31. Install the power steering pump and drive belt.
  32.  
  33. Reconnect all disconnected electrical connections and vacuum lines.
  34.  
  35. Reconnect the upper radiator hose and heater inlet hose.
  36.  
  37. Reinstall the spark plug wires to the spark plugs.
  38.  
  39. Install the engine ground wire to the valve cover. Reconnect the throttle cable from the throttle body.
  40.  
  41. Reinstall the air cleaner assembly and duct work that goes along with it. Reconnect the negative battery cable.
  42.  
  43. After installation, check to see that all hoses and wires are installed correctly.
  44.  
  45. Refill the coolant system.
  46.  
  47. Adjust the valve clearance. Make all other necessary adjustments
  48.  

It is recommended that after completing the cylinder head removal and installation, the engine oil should be changed.

1986-90 Legend

See Figures 9 and 10

The cylinder head temperature must be below 100°F.

Before removing the cylinder head check the following:



Inspect the timing belt.
 
Turn the flywheel so the No. 1 cylinder is at TDC.
 
Mark all wiring and emission hoses before disconnecting them.
 

  1. Disconnect the battery ground cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the vacuum hose from the brake booster.
  6.  
  7. Remove the secondary ground cable from the cylinder head and the transaxle housing.
  8.  
  9. Disconnect the radio noise condenser connector, ignition coil wire and the ignition primary connector.
  10.  
  11. Remove the air cleaner cover.
  12.  
  13. Relieve the fuel pressure by loosening the service bolt on the top of the fuel filter about a turn. Disconnect the fuel return hose from the pressure regulator. Remove the special nut and the fuel hose.
  14.  


CAUTION
The fuel system may be under pressure and fuel will be sprayed. Be sure there is good ventilation and take the appropriate fire safety precautions.

  1. Disconnect the throttle cable from the throttle valve.
  2.  
  3. Disconnect the charcoal canister hose from the throttle valve.
  4.  
  5. Disconnect the engine sub harness connectors from the cylinder head and the intake manifold:
    1. The 6 injector connectors.
    2.  
    3. The TA sensor connector.
    4.  
    5. The temperature unit connector.
    6.  
    7. The ground connector from the fuel pipe.
    8.  
    9. The TW sensor connector.
    10.  
    11. The throttle sensor connector.
    12.  
    13. The crankshaft angle sensor connector.
    14.  
    15. EGR valve connector.
    16.  
    17. The 4 wire harness clamps.
    18.  

  6.  
  7. Disconnect the oxygen sensor coupler.
  8.  
  9. Disconnect the cooling system hoses from the cylinder head. Remove the hose between the water passage and the intake manifold. Disconnect the connecting pipe to the valve body hose and bypass outlet hose.
  10.  
  11. Disconnect the spark plug wires from the spark plugs and remove the distributor assembly.
  12.  
  13. Remove the intake manifold cover from the intake manifold.
  14.  
  15. Remove the wire harness cover.
  16.  
  17. Remove the alternator pulley cover.
  18.  
  19. Remove the alternator and belt.
  20.  
  21. Remove the power steering pump and disconnect the pump hoses. Also, remove the hose clamp bolt on the body.
  22.  
  23. Disconnect the idle boost solenoid hoses.
  24.  
  25. Remove the cruise control actuator.
  26.  
  27. Remove the exhaust header pipe and pull it clear of the exhaust manifold.
  28.  
  29. Remove the air cleaner base mount bolts and disconnect the hose from the intake manifold to the breather chamber.
  30.  
  31. Remove the air cleaner base from the intake manifold.
  32.  
  33. Remove the EGR tube nuts from the cylinder head.
  34.  
  35. Remove the exhaust manifold cover nuts.
  36.  
  37. Remove the air suction tube nuts from the exhaust manifold and air suction valve.
  38.  
  39. Remove the intake manifold assembly from the cylinder head.
  40.  
  41. Remove the water passage assembly from the front and rear of the cylinder head.
  42.  
  43. Remove the timing belt upper covers.
  44.  
  45. Loosen the tensioner adjustment bolt and remove the timing belt.
  46.  

Advance the crankshaft by 15 degrees before removing the timing belt to prevent interference between the piston and the valve.

  1. Remove the front and rear camshaft pulleys using the following procedure:
    1. Before removing the rear pulley, adjust the cam position so no valve is fully open.
    2.  
    3. Remove the pulley mounting bolts with a universal holder and a double-end wrench. For the rear pulley, first, remove the top 2 bolts and then the remaining bolt.
    4.  

  2.  
  3. Remove the upper cover back plates.
  4.  
  5. Remove the valve covers and the head side covers.
  6.  
  7. Remove the bearing cap oil pipes, the bearing caps and the camshaft.
  8.  
  9. Remove the intake and exhaust inside rocker arms and pushrods.
  10.  

Label all valve train components to ensure installation in their proper locations.

  1. Remove the cylinder head bolts and remove the head.
  2.  

Unscrew the cylinder head bolts1/4of a turn in the reverse order of the torque sequence until loose to prevent warpage to the cylinder head.

  1. Clean the gasket mounting surfaces.
  2.  



Click image to see an enlarged view

Fig. Fig. 9: Cylinder head and valve train-1986-90 Legend



Click image to see an enlarged view

Fig. Fig. 10: Cylinder head bolt torque sequence-1986-90 Legend

To install:
  1. Use new gaskets and install the exhaust manifold onto the cylinder head and tighten the bolts in a crisscrosss pattern in 2-3 steps.
  2.  
  3. Install the cylinder head onto the engine block, after making sure the mating surface was cleaned and a new gasket was installed. Be sure to pay attention to the following points:
    1. Be sure the No. 1 cylinder is at TDC and the camshaft pulleys UP mark is on the top before positioning the head in place.
    2.  
    3. The cylinder head dowel pins and oil control jet must be aligned.
    4.  
    5. Torque the cylinder head bolts, in 2 progressive steps: First to 29 ft. lbs. (40 Nm), in sequence, then to 56 ft. lbs. (78 Nm), in the same sequence.
    6.  

  4.  
  5. Pour engine oil into the cylinder head hydraulic tappet mounting hole, up to the level of the oil path.
  6.  
  7. Install the hydraulic tappet into the cylinder head. Do not rotate the hydraulic tappet while inserting it into the head.
  8.  
  9. Pour engine oil into the oil fillers on the cylinder head.
  10.  
  11. Install the pushrods and rocker arms. Be sure to install each part in its original position. Loosen the rocker arm adjusting screws and locknuts before installation.
  12.  
  13. Install the camshafts and camshaft oil seals. Be sure to take note of the locations of the camshafts; the front camshaft has a groove for driving the distributor.
    1. Make sure the camshaft is mounted parallel with the rocker arm slipper surface.
    2.  
    3. Advance the crankshaft by 15 degrees from the No. 1 cylinder TDC of compression stroke to prevent interference between the piston and valve.
    4.  
    5. Place the rear camshaft on the cylinder head at the position where the cam is not pushing the valve.
    6.  
    7. Preset the oil seal, with its spring side facing inward.
    8.  
    9. Install the rear camshaft sealing rubber. Do not apply oil to the cam holder side of the oil seal.
    10.  

  14.  
  15. Apply liquid gasket to the camshaft oil seal mounting surface and on the head contact surface. Finger tighten the bearing caps.
  16.  
  17. Carefully fit the camshaft oil seal until it contacts the bearing cap. Torque the bearing cap bolts in 2 steps to 20 ft. lbs. (28 Nm) in the sequence shown. Make sure the oil seal is properly positioned and torque those bolts last to 9 ft. lbs. (12 Nm).
  18.  
  19. Install the upper timing cover plate. Install the camshaft pulley and torque the bolts to 23 ft. lbs. (32 Nm). Install the timing belt.
  20.  
  21. Install the water passage assembly from the front and rear of the cylinder head.
  22.  
  23. Install the intake manifold assembly and torque the bolts to 16 ft. lbs. (22 Nm).
  24.  
  25. Install the air suction tube nuts to the exhaust manifold and air suction valve.
  26.  
  27. Install the exhaust manifold cover nuts.
  28.  
  29. Install the EGR tube nuts to the cylinder head.
  30.  
  31. Install the air cleaner base to the intake manifold.
  32.  
  33. Install the air cleaner base mount bolts and reconnect the hose from the intake manifold to the breather chamber.
  34.  
  35. Install the exhaust header pipe to the exhaust manifold.
  36.  
  37. Install the cruise control actuator.
  38.  
  39. Reconnect the idle boost solenoid hoses.
  40.  
  41. Install the power steering pump and reconnect the pump hoses. Also, install the hose clamp bolt on the body.
  42.  
  43. Install the alternator and belt.
  44.  
  45. Install the alternator pulley cover.
  46.  
  47. Install the wire harness cover.
  48.  
  49. Install the intake manifold cover to the intake manifold.
  50.  
  51. Install the distributor assembly and reconnect the spark plug wires to the spark plugs.
  52.  
  53. Reconnect the cooling system hoses to the cylinder head. Install the hose between the water passage and the intake manifold. Reconnect the connecting pipe to the valve body hose and bypass outlet hose.
  54.  
  55. Reconnect the oxygen sensor and all disconnected electrical connections.
  56.  
  57. Reconnect the charcoal canister hose to the throttle valve.
  58.  
  59. Reconnect the throttle cable to the throttle valve.
  60.  
  61. Install all disconnected fuel lines. Install the air cleaner cover.
  62.  
  63. Install the secondary ground cable to the cylinder head and the transaxle housing.
  64.  
  65. Install the vacuum hose to the brake booster.
  66.  
  67. Refill the cooling system.
  68.  
  69. Reconnect the battery ground cable.
  70.  
  71. Readjust the exhaust valves:
    1. With the engine at TDC on No. 1 cyl., adjust cyl. 1, 2, and 4.
    2.  
    3. Turn the valve adjusting screw until it contacts the valve, then an additional 1.5 turns.
    4.  
    5. Turn the engine to TDC on No. 5 cyl. and adjust cyl. 3, 5, and 6.
    6.  

  72.  
  73. After the heads are reassembled, make sure the engine sits for approximately 5 minutes to allow the hydraulic tappets to reach the proper oil level.
  74.  
  75. Remove the spark plugs and crank the engine, feel for compression at each cylinder at the spark plug holes. It may be necessary to crank the engine through several cycles to confirm compression.
  76.  
  77. If any cylinder does not have compression, it may be necessary to disassemble the head and check the suspected tappet.
  78.  
  79. If all cylinders have compression, reinstall the plugs and start the engine.
  80.  

1991-93 Legend

See Figures 11, 12 and 13

The cylinder head temperature must be below 100°F.

Before removing the cylinder head check the following:



Inspect the timing belt.
 
Turn the flywheel so the No. 1 cylinder is at TDC.
 
Mark all wiring and emission hoses before disconnecting them.
 

  1. Remove the battery and battery box.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the vacuum hose from the brake booster.
  6.  
  7. Remove the secondary ground cable from the cylinder head and block.
  8.  
  9. Remove the air cleaner and ducting.
  10.  
  11. Relieve the fuel pressure by loosening the service bolt on the top of the fuel filter about a turn. Disconnect the fuel return hose from the pressure regulator. Remove the special nut and the fuel hose.
  12.  


CAUTION
The fuel system may be under pressure and fuel will be sprayed. Be sure there is good ventilation and take the appropriate fire safety precautions.

  1. Disconnect the throttle cable from the throttle valve.
  2.  
  3. Disconnect the charcoal canister hose from the throttle valve.
  4.  
  5. Disconnect the wiring and remove the main fuse box.
  6.  
  7. Remove the injector resistor and the connector.
  8.  
  9. Unplug the connectors and remove the ignition coils.
  10.  
  11. Remove the engine wire harness covers and disconnect the following:
    1. The 6 injector connectors.
    2.  
    3. The TA sensor connector.
    4.  
    5. The temperature unit connector.
    6.  
    7. The ground connector from the fuel pipe.
    8.  
    9. The TW sensor connector.
    10.  
    11. The EGR valve connector.
    12.  
    13. The knock sensor.
    14.  
    15. The crankshaft angle/cylinder sensor connector.
    16.  

  12.  
  13. Remove the air inlet pipe and vacuum pipes and hoses.
  14.  
  15. Disconnect the throttle sensor, oil pressure switch, oxygen sensors and engine ground terminals and remove the wiring harness.
  16.  
  17. Remove the intake manifold.
  18.  
  19. Remove the upper timing belt covers.
  20.  
  21. Do not remove the timing belt adjuster bolt. Loosen it 1 / 2 turn, relieve the belt tension and tighten the bolt.
  22.  
  23. Remove the camshaft timing belt and the camshaft pulleys.
  24.  
  25. Remove the timing belt cover plates from the heads and remove the crank angle/cylinder sensor from the left head.
  26.  
  27. Remove the cylinder head covers.
  28.  
  29. Remove the bolts from the alternator and power steering pump brackets as required.
  30.  
  31. Remove the self locking nuts from the exhaust manifolds and slip the manifolds off. If necessary, remove the camshafts.
  32.  
  33. Loosen each head bolt about 1 / 2 turn in the opposite of the installation sequence. This is important to prevent warping the heads. Repeat until all bolts are loose and the head can be removed.
  34.  



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Fig. Fig. 11: Cylinder head and valve train-1991-93 Legend



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Fig. Fig. 12: Cylinder head bolt loosening sequence-1991-93 Legend



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Fig. Fig. 13: Cylinder head bolt torque sequence-1991-93 Legend

To install:
  1. It is easier to install the exhaust manifolds and their covers onto the heads before installing the heads to the engine. Use new gaskets and self-locking nuts and torque to 25 ft. lbs. (34 Nm).
  2.  
  3. Install the heads with new gaskets and O-rings, making sure the dowel pins and control orifices are properly positioned. Oil the threads and washers on the head bolts and torque in 2 steps in the sequence shown to 56 ft. lbs. (78 Nm).
  4.  
  5. Apply liquid gasket to the corners of the camshaft holders and install the cylinder head covers.
  6.  
  7. Install the crankshaft/cylinder sensor to the left cylinder head, then install both timing belt cover plates.
  8.  
  9. Install the camshaft pulleys and torque the bolts to 23 ft. lbs. (32 Nm). There is a left and right pulley; the left one goes with the crankshaft/cylinder sensor.
  10.  
  11. Align the timing marks on the crankshaft and camshaft pulleys, install the timing belt and adjust the belt tension. Install the timing belt covers.
  12.  
  13. Install the intake manifold with new gaskets. Torque the 6mm bolts to 9 ft. lbs. (12 Nm) and the 8mm bolts to 16 ft. lbs. (22 Nm). Connect the cooling system hoses.
  14.  
  15. Install the air suction, EGR, vacuum and air inlet pipes. Reconnect the vacuum and fuel system hoses, using new gaskets on the fuel supply hose.
  16.  
  17. Connect the sensor wiring and install the wiring harness for the injection and ignition systems.
  18.  
  19. Install the fuse box and connect the wiring.
  20.  
  21. Connect the throttle cable and refill the cooling system.
  22.  
  23. Make sure all other wires and hoses are properly connected and install the battery. Before starting the engine, turn the ignition switch ON and OFF a number of times to pressurize the fuel system. Check for leaks.
  24.  
  25. After starting the engine, bleed the cooling system.
  26.  

Vigor

See Figures 14, 15 and 16

The radio is equipped with a theft protection program. Be sure the 5 digit security code is available before disconnecting the battery.

  1. Disconnect the negative battery cable and drain the coolant.
  2.  
  3. Remove the fuel filler cap and loosen the service bolt on the fuel filter banjo bolt to relieve the fuel system pressure. Remove the banjo bolt to remove the fuel feed hose from the fuel filter. Remove the fuel return hose from the pressure regulator.
  4.  


CAUTION
The fuel system may be under pressure and fuel will be sprayed. Be sure there is good ventilation and take the appropriate fire safety precautions.

  1. Remove the intake air duct and air cleaner assembly.
  2.  
  3. Remove the throttle cable by loosening the locknut, then slip the cable end out of the throttle bracket and accelerator linkage. Take care not to bend the cable when removing it. Unbolt the throttle cable clamp and move the cable aside.
  4.  
  5. Label and disconnect the fuel and vacuum hoses from the intake manifold.
  6.  
  7. Disconnect the heater hoses and the brake booster hose.
  8.  
  9. Disconnect the wiring from the ignition coil and the ground wire.
  10.  
  11. Remove the ABS motor relay box and the battery heat shield.
  12.  
  13. Remove the 2 bolts to remove the distributor. Be careful not to drop the collar behind the distributor.
  14.  
  15. Label and disconnect all the wiring from the cylinder head.
  16.  
  17. Disconnect the remaining coolant hoses from the intake manifold.
  18.  
  19. Remove the intake manifold support brackets. The manifold will be removed after removing the cylinder head.
  20.  
  21. Remove the oxygen sensor.
  22.  
  23. Remove the exhaust manifold heat shields and disconnect the exhaust pipe from the manifold.
  24.  
  25. Remove the support bracket and remove the exhaust manifold.
  26.  
  27. Remove the cylinder head cover and the upper timing belt cover.
  28.  
  29. Rotate the crankshaft to bring No. 1 piston to TDC on the compression stroke. The camshaft sprocket is equipped with TDC marks that align with the edge of the cylinder head.
  30.  
  31. Inspect the condition of the belt. If it is not being replaced, use paint to matchmark the belt to the sprocket for reassembly.
  32.  
  33. Loosen the belt tension adjuster bolt and push the tensioner against the spring to release the tension on the camshaft belt, then tighten the bolt again. Carefully slide the belt off the camshaft sprocket.
  34.  
  35. Loosen each cylinder head bolt about 1 / 2 turn in the opposite of the installation sequence. This is important to prevent warping the head. Repeat until all bolts are loose and can be removed.
  36.  
  37. If the cylinder head is stuck to the block, there are pry points near the No. 9 and No. 11 cylinder head bolts. Do not pry against the gasket surfaces.
  38.  
  39. After removing the cylinder head, remove the intake manifold.
  40.  



Click image to see an enlarged view

Fig. Fig. 14: Cylinder head and valve train-Vigor



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Fig. Fig. 15: Cylinder head bolt loosening sequence-Vigor



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Fig. Fig. 16: Cylinder head bolt torque sequence-Vigor

To install:
  1. Make sure the cylinder head and the engine block sealing surfaces are flat. Repair or replace as required. Clean all gasket surfaces and run a tap through the bolt holes in the block to clean the threads.
  2.  
  3. Fit a new O-ring onto the oil control orifice and install the orifice and dowel pins onto the block. Lay the new head gasket in place.
  4.  
  5. Install the intake manifold onto the cylinder head with a new gasket. Torque the nuts in a crisscross pattern in 2 steps to 16 ft. lbs. (22 Nm).
  6.  
  7. Make sure the crankshaft and camshaft are both at TDC for No. 1 piston and fit the cylinder head to the block. Make sure the oil control orifice is properly aligned.
  8.  
  9. Lightly oil the threads and washer surfaces of the cylinder head bolts and install them. Torque the bolts in 3 steps to 72 ft. lbs. (100 Nm) in the correct sequence.
  10.  
  11. Install the intake manifold brackets.
  12.  
  13. Loosely install the exhaust manifold bracket onto the manifold. Install the exhaust manifold with a new gasket and new self-locking nuts and torque the nuts to 23 ft. lbs. (32 Nm).
  14.  
  15. Connect the exhaust pipe and install the manifold shields.
  16.  
  17. Install the oxygen sensor.
  18.  
  19. If the crankshaft was not turned while the engine was apart and there is a matchmark on the timing belt and camshaft pulley, make sure the marks are aligned and slide the belt onto the camshaft sprocket. If the engine has been disturbed and the matchmark is not usable:
    1. Align the white TDC mark on the crankshaft pulley with the pointer on the lower belt cover. Rotate the crankshaft slowly. If it stops, a piston is contacting the valves. Turn the camshaft to move the valves and try again.
    2.  
    3. On the camshaft sprocket, make sure the UP mark is up and align the TDC marks with the edge of the cylinder head.
    4.  
    5. Install the timing belt with no slack between the camshaft and crankshaft sprockets.
    6.  
    7. To adjust the belt tension, loosen the tensioner bolt, turn the crankshaft counterclockwise about 1 / 4 turn, then tighten the bolt again. Rotate the crankshaft 2 full turns and make sure the timing marks and the TDC mark align properly.
    8.  

  20.  
  21. Adjust the valves.
  22.  
  23. Apply silicone sealer to the ends of the cylinder head near the camshaft holders. Install the cylinder head cover with new rubber seals as required.
  24.  
  25. Install the timing belt covers.
  26.  
  27. Connect all wiring, hoses, vacuum lines and control cables. Adjust as required.
  28.  
  29. Change the oil and refill all fluids. Run the engine to bleed the cooling system and check for leaks.
  30.  

CLEANING AND INSPECTION



See Figures 17, 18 and 19

Although cylinder head service can be performed by most do it yourself mechanics, some operations are best performed by a competent machine shop.

  1. Refer to "Valves, Removal and Installation" in this section and remove the valve assemblies from the cylinder head.
  2.  
  3. Using a small wire power brush, clean the carbon from the combustion chambers and the valve ports.
  4.  



Click image to see an enlarged view

Fig. Fig. 17: Checking the cylinder head for flatness



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Fig. Fig. 18: Check the cylinder head in all of these directions to get the best measurement



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Fig. Fig. 19: Checking valve stem-to-guide clearance using a dial indicator

  1. Inspect the cylinder head for cracks in the exhaust ports, combustion chambers or external cracks in the water chamber.
  2.  
  3. Thoroughly clean the valve guides using a suitable wire bore brush.
  4.  

Excessive valve stem-to-bore clearance will cause excessive oil consumption and may cause valve breakage. Insufficient clearance will result in noisy and sticky functioning of the valve and disturb engine smoothness.

  1. Measure the valve stem clearance as follows:
    1. Clamp a dial indicator on one side of the cylinder head rocker arm cover gasket rail.
    2.  
    3. Locate the indicator so movement of the valve stem from side-to-side (crosswise to the head) will cause a direct movement of the indicator stem. The indicator stem must contact the side of the valve stem just above the valve guide.
    4.  
    5. Prop the valve head about 1/16 in. off the valve seat.
    6.  
    7. Move the stem of the valve from side-to-side using light pressure to obtain a clearance reading. If the clearance exceeds specifications, it will be necessary to ream (for original valves) the valve guides.
    8.  

  2.  
  3. Inspect the rocker arm studs for wear or damage.
  4.  
  5. Install a dial micrometer into the valve guide and check the valve seat for concentricity.
  6.  

RESURFACING



  1. Using a straight edge and feeler gauge, check the cylinder for warpage.
  2.  
  3. If the warpage exceeds 0.002 inch over the total length, the cylinder head must be resurfaced. Resurfacing can be performed at most machine shops.
  4.  

 
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