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Home >> Subaru >> 2021 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel Injection System (2.5L) >> Intake Manifold >> Assembly
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Intake Manifold: Assembly

  1. Apply liquid gasket to the nipple threads, and install the nipple to the intake manifold.

    Liquid gasket: 

    THREE BOND 1105 (Part No. 004403010) or equivalent

    Tightening torque: 

    T1: 17 N.m (1.7 kgf-m, 12.5 ft-lb)

    T2: 25 N.m (2.5 kgf-m, 18.4 ft-lb)

    Fig 1: Intake Manifold Nipples (With Torque Specification)
    G08538706Courtesy of SUBARU OF AMERICA, INC.
  2. Install the tumble generator valve assembly onto intake manifold.
    NOTE: Use a new gasket.

    Tightening torque: 

    8.2 N.m (0.8 kgf-m, 6.0 ft-lb)

    G06344612Courtesy of SUBARU OF AMERICA, INC.
  3. Install the air intake duct to the intake manifold.

    Tightening torque: 

    17 N.m (1.7 kgf-m, 12.5 ft-lb)

    G11571522Courtesy of SUBARU OF AMERICA, INC.
  4. Install the fuel pipe assembly to the intake manifold.

    Tightening torque: 

    6.4 N.m (0.7 kgf-m, 4.7 ft-lb)

    G05333518Courtesy of SUBARU OF AMERICA, INC.
  5. Install the fuel injector pipe LH and connect the LH side fuel hose to the fuel injector pipe LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (STI)>FUEL DELIVERY, RETURN AND EVAPORATION LINES>INSTALLATION>CONNECTING THE FUEL DELIVERY HOSE, FUEL RETURN HOSE AND FUEL HOSE .
    NOTE: Use a new fuel hose.
    G08538701Courtesy of SUBARU OF AMERICA, INC.
  6. Install the fuel injector pipe RH and connect the RH side fuel hose to the fuel injector pipe RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (STI)>FUEL DELIVERY, RETURN AND EVAPORATION LINES>INSTALLATION>CONNECTING THE FUEL DELIVERY HOSE, FUEL RETURN HOSE AND FUEL HOSE .
    NOTE: Use a new fuel hose.
    G08538700Courtesy of SUBARU OF AMERICA, INC.
  7. Install the engine harness to the intake manifold and attach the harness brackets holding the engine harness.

    Tightening torque: 

    19 N.m (1.9 kgf-m, 14.0 ft-lb)

    G06344607Courtesy of SUBARU OF AMERICA, INC.
  8. Install the fuel injector.
    NOTE: Use new O-rings, rubbers and seal rings.
    G06344606Courtesy of SUBARU OF AMERICA, INC.
  9. Install the bolts which hold fuel injector pipe.
    • RH side

      Tightening torque: 

      19 N.m (1.9 kgf-m, 14.0 ft-lb)

      G06344603Courtesy of SUBARU OF AMERICA, INC.
    • LH side

      Tightening torque: 

      6.4 N.m (0.7 kgf-m, 4.7 ft-lb)

    G06344604Courtesy of SUBARU OF AMERICA, INC.

    Tightening torque: 

    19 N.m (1.9 kgf-m, 14.0 ft-lb)

    G06344605Courtesy of SUBARU OF AMERICA, INC.
  10. Connect the connector to the tumble generator valve assembly.
    G08538694Courtesy of SUBARU OF AMERICA, INC.
  11. Connect the connectors to the fuel injector.
    G06344601Courtesy of SUBARU OF AMERICA, INC.
  12. Secure the engine harness to the fuel injector pipe with the harness band (A).
    • RH side
      G08538691Courtesy of SUBARU OF AMERICA, INC.
    • LH side
    G08538692Courtesy of SUBARU OF AMERICA, INC.
  13. Install the throttle body to the intake manifold.
    NOTE: Use a new gasket.

    Tightening torque: 

    8 N.m (0.8 kgf-m, 5.9 ft-lb)

    G08538690Courtesy of SUBARU OF AMERICA, INC.
  14. Secure the engine harness and vacuum hose using the clip (A), and secure the engine harness to the engine harness stay using the clip (B), and install the bolt which holds the engine harness to the intake manifold.

    Tightening torque: 

    19 N.m (1.9 kgf-m, 14.0 ft-lb)

    G06344597Courtesy of SUBARU OF AMERICA, INC.
  15. Connect connector (A) to the throttle position sensor and connector (B) to the manifold pressure sensor.
    G08538688Courtesy of SUBARU OF AMERICA, INC.
  16. Install the engine ground terminal to intake manifold.

    Tightening torque: 

    19 N.m (1.9 kgf-m, 14.0 ft-lb)

    G06344595Courtesy of SUBARU OF AMERICA, INC.
  17. Install the solenoid valve bracket together with the wastegate control solenoid valve.

    Tightening torque: 

    T1: 6.4 N.m (0.7 kgf-m, 4.7 ft-lb)

    T2: 19 N.m (1.9 kgf-m, 14.0 ft-lb)

    Fig 2: Solenoid Valve Bracket, Wastegate Control Solenoid Valve And Bolts (With Torque Specification)
    G11571544Courtesy of SUBARU OF AMERICA, INC.
  18. Connect the vacuum hose (B) to the intake duct, then connect the connector (A) to the wastegate control solenoid valve.
    G11571504Courtesy of SUBARU OF AMERICA, INC.
  19. Install purge control solenoid valve 1 and purge control solenoid valve 2.
    NOTE: Connect the vacuum hose and vacuum control hose as shown in the figure.
    G13640062Courtesy of SUBARU OF AMERICA, INC.

    Tightening torque: 

    T1: 6.4 N.m (0.7 kgf-m, 4.7 ft-lb)

    T2: 19 N.m (1.9 kgf-m, 14.0 ft-lb)

    Fig 3: Purge Control Solenoid Valve (1, 2) (With Torque Specification)
    G08538728Courtesy of SUBARU OF AMERICA, INC.
  20. Attach the connector to the PCV hose assembly.
    G08538683Courtesy of SUBARU OF AMERICA, INC.
  21. Install the connector to the intake duct.
    G08538682Courtesy of SUBARU OF AMERICA, INC.
  22. Install the fuel pipe protector LH.

    Tightening torque: 

    19 N.m (1.9 kgf-m, 14.0 ft-lb)

    G08538681Courtesy of SUBARU OF AMERICA, INC.
  23. Install the fuel pipe protector RH, and secure the engine harness to the fuel pipe protector RH using the clip (A).

    Tightening torque: 

    19 N.m (1.9 kgf-m, 14.0 ft-lb)

    G08538680Courtesy of SUBARU OF AMERICA, INC.