LS400 1990-1997

Fuel Rail (Supply Manifold) & Injectors

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Removal & Installation



Specific to:

Lexus LS400 1993-1994

  1. Disconnect the negative battery cable. Wait at least 90 seconds before proceeding with any other work.
  2.  
  3. Drain the engine coolant.
  4.  
  5. Remove the battery clamp cover.
  6.  
  7. Remove the air cleaner cover. Remove the air cleaner hose or duct.
  8.  
  9. Remove the battery.
  10.  
  11. Remove the cover from the engine compartment relay box.
  12.  
  13. Remove the air cleaner.
  14.  
  15. Remove the throttle body cover.
  16.  
  17. At the throttle body, disconnect the accelerator cable, the transmission throttle control cable and the cruise control actuator cable.
  18.  
  19. Disconnect the air hose from the IAC valve and the hose from the PS air control valve at the intake air connector. Remove the clamp bolt holding the intake air connector to the throttle body. Remove the intake air connector.
  20.  
  21. Remove the upper ignition wire cover. Remove the right engine wire harness cover.
  22.  
  23. Remove the left engine wiring cover.
  24.  
  25. Remove the right No. 3 (upper) timing belt cover.
  26.  
  27. Disconnect the EVAP hose from the clamp on the left timing belt No. 3 cover. Remove the 4 bolts. Disconnect the grommet from the timing belt cover and remove the cover. Remove the cord grommet.
  28.  
  29. Remove the lower ignition wire cover. It will be necessary to disconnect the high-tension wire from the right ignition coil.
  30.  
  31. Disconnect the radiator hoses from the water inlet housing and from the front water bypass joint.
  32.  
  33. Remove the throttle body.
  34.  
  35. Disconnect the following:
    1. IAC valve connector
    2.  
    3. EGR valve connector
    4.  
    5. VSV connectors for the fuel pressure control system and the EVAP system
    6.  
    7. EGR gas temperature sensor connector
    8.  
    9. VSV for the AIR system, if so equipped.
    10.  

  36.  
  37. Disconnect the following:
    1. Water bypass hose from the IAC valve.
    2.  
    3. PS air control hose from the air intake chamber.
    4.  
    5. Fuel pressure regulator vacuum sensing hose from the vacuum pipe.
    6.  
    7. Coolant bypass hose from the EGR valve.
    8.  
    9. Brake booster vacuum hose from the air intake chamber.
    10.  
    11. AIR system VSV hose from the AIR pump outlet pipe.
    12.  
    13. PCV hose from the left cylinder head cover.
    14.  

  38.  
  39. Remove the VSVs. Disconnect the DIAGNOSIS data link connector from the air intake chamber. Remove the air intake chamber.
  40.  
  41. Disconnect the fuel inlet pipe from the delivery pipe. Remove the pulsation damper.
  42.  
  43. Disconnect the fuel return hose from the return pipe.
  44.  
  45. Disconnect the wiring harness from the clips and brackets on the right cylinder head. Remove the wire brackets from the cylinder head. Disconnect the engine wiring harness from the intake manifold.
  46.  
  47. Disconnect the engine wiring harness from the delivery pipes. Disconnect the injector wiring connectors.
  48.  
  49. Disconnect the wire harness from the rear water bypass joint.
  50.  
  51. Remove the fuel return pipe. Remove the fuel delivery pipes and the remove the injectors. Take care not to drop or damage the injectors.
  52.  
  53. Remove the spacers and insulators. Pull out the injectors from the delivery pipes. Remove the O-ring and grommet from each injector.
  54.  

To install:

  1. Install a new grommet to the injector. Apply a light coat of gasoline to each new O-ring and carefully install them on each injector.
  2.  
  3. Install the injectors to the delivery pipes; push them into place while turning them to the left and right. Make sure the injectors rotate smoothly in the delivery pipe. Position the wiring connector outward.
  4.  
  5. Place the insulators and the spacers in the proper position on the intake manifold.
  6.  
  7. Install the injectors together with the delivery pipe in the proper position on the intake manifold.
    NOTE
    Make sure the injectors rotate smoothly. If not, the probable cause is the incorrect installation of the O-rings. Disassemble the injectors and replace the O-rings.

  8.  
  9. Install the fuel return pipe. Tighten the union bolt at the pressure regulator to 26 ft. lbs. (35 Nm).
  10.  
  11. Tighten the locknut on the fuel pressure regulator to 22 ft. lbs. (29 Nm).
  12.  
  13. Connect the engine wiring harness to the rear water bypass joint. On California vehicles, connect the harness connectors.
  14.  
  15. Connect the injector connectors to the injectors. Connect the wiring connectors to the left delivery pipe. Install the harness protector.
  16.  
  17. Install the engine wiring to the intake manifold.
  18.  
  19. Install the wire harness brackets onto the right cylinder head. Secure the harness to the brackets and install the protector.
  20.  
  21. Connect the fuel return hose to the return pipe; connect the fuel inlet hose to the left delivery pipe. Always use new gaskets. Using a torque wrench with a fulcrum length of 30mm (11.81 in), tighten the union bolt at the pulsation damper to 29 ft. lbs. (39 Nm).
  22.  
  23. Install the air intake chamber. Tighten the bolts holding the EGR pipe to the chamber and to the right cylinder head to 13 ft. lbs. (18 Nm). Install the accelerator bracket. Install new gaskets and connect the union with the union bolt. Tighten the bolt to 22 ft. lbs. (29 Nm).
  24.  
  25. Connect the brake booster vacuum hose to the union on the intake chamber. Connect the vacuum hose from the AIR VSV to the intake chamber. Connect the other vacuum hose to the AIR outlet pipe.
  26.  
  27. Install the following:
    1. Water hose to the EGR
    2.  
    3. Brake booster hose to the air intake chamber
    4.  
    5. AIR VSV hose to the AIR pump outlet pipe, if so equipped.
    6.  
    7. PCV hose to the left cylinder head cover.
    8.  
    9. Water bypass hose to the IAC valve.
    10.  
    11. PS air control valve to the air intake chamber.
    12.  
    13. Fuel pressure regulator vacuum hose to the vacuum pipe.
    14.  

  28.  
  29. Connect the following:
    1. IAC valve connector
    2.  
    3. EGR valve connector
    4.  
    5. VSV connectors for the fuel pressure control system and the EVAP system
    6.  
    7. EGR gas temperature sensor connector
    8.  
    9. VSV for the AIR system, if so equipped.
    10.  

  30.  
  31. Before installing the throttle body, place a new gasket in position on the air intake chamber. Install the throttle body. Use the 40mm (1.57 in) bolts and tighten them to 13 ft. lbs. (18 Nm). Connect the water bypass pipe to the clamp on the wire cover. Connect the electrical connectors to the throttle body.
  32.  
  33. Connect the radiator hoses to the front water bypass joint and the water inlet housing.
  34.  
  35. Install the lower high-tension wire cover. Connect the coil lead to the right coil.
  36.  
  37. Install the right timing belt cover.
  38.  
  39. Install the 3 gaskets on the left timing belt cover. Install the cord grommet to the high tension cord. Install the grommet to the timing belt cover and install the cover with the 4 bolts. Connect the vacuum hose to the EVAP BVSV.
  40.  
  41. Install the upper ignition wire cover and the right engine wire harness cover.
  42.  
  43. Install the left engine wire cover. Make certain all lines and hoses are properly retained within the clips.
  44.  
  45. Install the intake air connector pipe. Connect the air connector pipe to the throttle body. Connect the air hoses to the IAC valve and to the PS air control valve.
  46.  
  47. Reconnect the accelerator, transmission throttle control and cruise control cables.
  48.  
  49. Reinstall the throttle body cover.
  50.  
  51. Install the air cleaner. Connect the VAF meter connector.
  52.  
  53. Install the relay box cover.
  54.  
  55. Reinstall the battery; do not connect the negative terminal.
  56.  
  57. Install the air hose and air cleaner cover.
  58.  
  59. Install the battery clamp cover. Connect the negative battery cable.
  60.  
  61. Refill the engine with coolant.
  62.  
  63. Start the engine and check for leaks of fuel or coolant. Recheck the coolant level.
  64.  

Specific to:

Lexus LS400 1995-1997

  1. Disconnect the negative battery cable. Wait at least 90 seconds before proceeding with any other work.
  2.  
  3. Drain the engine coolant.
  4.  
  5. Relieve the fuel pressure from the fuel lines.
  6.  
  7. Remove the V bank cover by removing the bolt and two cap nuts.
  8.  
  9. Remove the air cleaner and intake air connector assembly.
  10.  
  11. Remove the left hand No. 3 timing belt cover.
  12.  
  13. Remove the air intake chamber assembly.
  14.  
  15. Tag and disconnect the following connectors:

    TPS connector
     
    With TRAC system, sub throttle position sensor connector
     
    With TRAC system, sub throttle actuator connector
     
    IAC valve connector
     
    EGR valve connector
     
    VSV connector for fuel pressure control
     
    VSV connector for EVAP system
     
    EGR gas temperature sensor connector
     

  16.  
  17. Disconnect the following hoses:

    Brake booster vacuum hose from the union on the air intake chamber
     
    PCV hose from the PCV valve on the left hand cylinder head
     
    Water bypass hose (from the EGR valve) from the rear water bypass joint
     
    Water bypass hose (from the throttle body) from the rear water bypass joint
     
    Vacuum hose (from the VSV for fuel pressure control) from the fuel pressure regulator
     
    EVAP hose (from charcoal canister) from the VSV for EVAP
     

  18.  
  19. Disconnect the heater hose from the water bypass pipe.
  20.  
  21. Disconnect the fuel inlet hose from the delivery pipe.
  22.  
  23. Disconnect the vacuum sensing hose and fuel return hose from the pressure regulator.
  24.  
  25. Disconnect the engine wire from the delivery pipes.
  26.  
  27. Remove the four nuts holding the delivery pipe to the intake manifold.
  28.  
  29. Remove the two connector brackets, the two delivery pipes and the fuel injector assembly. Remove the four spacers and eight insulators.
  30.  
  31. Pull out the eight injectors from the delivery pipes.
  32.  
  33. Remove the O-ring and grommet from each injector.
  34.  

To install:

  1. Install a new grommet to each injector.
  2.  
  3. Apply a light coat of gasoline to a new O-ring and install it to each injector.
  4.  
  5. While turning the injector clockwise and counterclockwise, push it onto the delivery pipes. Install all eight injectors in the same manner.
  6.  
  7. Position the injector connector outward.
  8.  
  9. Place eight new insulators and the four spacers on the intake manifold.
  10.  
  11. Place the eight injectors and two delivery pipes assembly in position on the intake manifold.
  12.  
  13. Temporarily install the two connector brackets and four mounting bolts.
  14.  
  15. Check that the injectors rotate smoothly.
  16.  
  17. Position the injector connector outward.
  18.  
  19. Tighten the four nuts holding the delivery pipes to the intake manifold. Torque the nuts to 13 ft. lbs. (18 Nm).
  20.  
  21. Connect the engine wire to the delivery pipes.
  22.  
  23. Connect the fuel return hose and vacuum sensing hose to the pressure regulator.
  24.  
  25. Connect the fuel inlet hose to the left hand delivery pipe.
  26.  
  27. Install the air intake chamber assembly, VSV for fuel pressure control and the VSV for EVAP by installing the four bolts and eight nuts. Uniformly tighten the bolts and nuts in several passes. Torque the bolts and nuts to 13 ft. lbs. (18 Nm).
  28.  
  29. Install the No. 2 EGR pipe with the two bolts and two nuts. Torque the two bolts and two nuts to 17 ft. lbs. (23 Nm).
  30.  
  31. Connect the heater hose to the water bypass pipe.
  32.  
  33. Connect the following hoses:

    Brake booster vacuum hose to the union on the air intake chamber
     
    PCV hose to the PCV valve on the left hand cylinder head
     
    Water bypass hose (from EGR valve) to the rear water bypass joint
     
    Water bypass hose (from throttle body) to the rear water bypass joint
     
    Vacuum hose (from VSV for fuel pressure control) to the fuel pressure regulator
     
    EVAP hose (from charcoal canister) from the VSV for EVAP
     

  34.  
  35. Connect the following connectors:

    TPS connector
     
    With TRAC system, sub TPS connector
     
    With TRAC system, sub throttle actuator connector
     
    IAC valve connector
     
    EGR valve connector
     
    EGR gas temperature sensor connector
     
    VSV connector for fuel pressure control
     
    VSV connector for EVAP
     

  36.  
  37. Install the accelerator bracket with the two bolts.
  38.  
  39. Connect the accelerator cable, A/T throttle control cable and the cruise control actuator cable.
  40.  
  41. Install the left hand No. 3 timing belt cover.
  42.  
  43. Install the air cleaner and intake air connector assembly.
  44.  
  45. Install the V bank cover.
  46.  
  47. Fill the engine with coolant.
  48.  
  49. Connect the negative battery cable to the battery.
  50.  
  51. Start the engine and check for leaks.
  52.  
  53. Recheck engine coolant level.
  54.  

 
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