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Fuel Pressure: Inspection

WARNING: This page is about a different variant/trim than selected.
  1. Release the fuel pressure. Refer to FUEL INJECTION (FUEL SYSTEMS) (STI)>FUEL>PROCEDURE>RELEASING OF FUEL PRESSURE .
  2. Open the fuel filler lid and remove the fuel filler cap.
    NOTE: This operation is required to release the inner pressure of the fuel tank.
  3. Disconnect the fuel delivery hose from the fuel delivery pipe, and connect the fuel pressure gauge.
    CAUTION:
    • Be careful not to spill fuel.
    • Catch the fuel from hoses using a container or cloth.
    1. Attach ST to the fuel delivery pipe and push ST in the direction of arrow mark to disconnect the quick connector of the fuel delivery hose.
      ST 42099AE000 QUICK CONNECTOR RELEASE
      G08539160Courtesy of SUBARU OF AMERICA, INC.
    2. Connect the fuel pressure gauge with ST1 and ST2.
    NOTE: ST1 is a SUBARU genuine part.
    ST1 42075AG690 FUEL HOSE
    ST2 18471AA000 FUEL PIPE ADAPTER
    G08539161Courtesy of SUBARU OF AMERICA, INC.
  4. Start the engine.
  5. Check the fuel pressure while disconnecting pressure regulator vacuum hose from intake manifold.
    NOTE:
    • The fuel pressure gauge registers 10 to 20 kPa (0.1 to 0.2 kg/cm2 , 1 to 3 psi) higher than standard values during high-altitude operations.
    • If the fuel pressure is out of specification, check or replace the fuel pump, fuel line, pressure regulator & damper assembly, and pressure regulator vacuum hose.

    Fuel pressure: 

    Standard 

    284 - 314 kPa (2.9 - 3.2 kg/cm2 , 41 - 46 psi)

  6. After connecting the vacuum hose to the pressure regulator, check the fuel pressure again.
    NOTE:
    • The fuel pressure gauge registers 10 to 20 kPa (0.1 to 0.2 kg/cm2 , 1 to 3 psi) higher than standard values during high-altitude operations.
    • If the fuel pressure is out of specification, check or replace the fuel pump, fuel line, pressure regulator & damper assembly, and pressure regulator vacuum hose.

    Fuel pressure: 

    Standard 

    230 - 260 kPa (2.4 - 2.7 kg/cm2 , 33 - 38 psi)

  7. After inspection, install the related parts in the reverse order of removal.
    CAUTION:
    • Before removing the fuel pressure gauge, release the fuel pressure.
    • Be careful not to spill fuel.
    • Catch the fuel from hoses using a container or cloth.
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