Fuel Line Pressure Inspection

2008 Mazda 6 s Sport, 4D Hatchback, StandardSECTION Fuel Line Pressure Inspection
WARNING: This page is about a different car, the 2008 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
  • Fuel line spills and leakage from the pressurized fuel system are dangerous. Fuel can ignite and cause serious injury or death and damage. To prevent this, complete the following inspection with the engine stopped. 
  1. Follow the before repair procedure and perform the fuel line safety procedure. (See BEFORE REPAIR PROCEDURE ).
  2. Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION )
  3. Disconnect the engine compartment side quick release connector. (See QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION ).
  4. Turn the lever of the SST parallel to the hose as shown in the figure.
  5. Fig 1: Inspecting Fuel Line Pressure
    G04562817Courtesy of MAZDA MOTORS CORP.
  6. Reconnect the quick release connector of the SST  to the fuel pipe until a click is heard.
  7. Verify that the quick release connector is firmly connected by pulling it by hand.
  8. Connect the negative battery cable.
    CAUTION:
    • Shorting the wrong terminal of the check connector may cause malfunctions. Make sure to short only the specified terminal. 
  9. Ground the check connector terminal F/P using the jumper wire.
    Fig 2: Locating Check Connector
    G04562820Courtesy of MAZDA MOTORS CORP.
  10. Turn the ignition switch to the ON position and operate the fuel pump.
  11. Measure the fuel line pressure.
    • If not within the specification, inspect or replace the following parts:

      If it is less than the specification 

      • Fuel pump unit
      • Fuel line leakage

      If it is more than the specification 

      • Fuel pump unit
      • Fuel line clogging

    Fuel line pressure 

    375-450 kPa {3.83-4.58 kgf/cm 2  , 54.4-65.2 psi} 

  12. Disconnect the jumper wire and stop the fuel pump.
  13. Wait 5 min and measure the fuel hold pressure.
    • If it is within the specification, inspect the following.
      • Fuel line for clogging or leakage

    Fuel hold pressure 200 kPa {2.0 kgf/cm 2  , 29 psi} 

  14. Disconnect the SST  .
  15. Connect the quick release connector. (See QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION ).
  16. Inspect all parts by performing the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ).
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.