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Fuel Pressure Test

  1. Release the residual pressure in fuel line.

    (Refer to " RELEASE RESIDUAL PRESSURE  ") 

    CAUTION: When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the KDS after completion of "Release Residual Pressure in Fuel Line" work.
  2. Open the clamp cover (A) and disconnect the fuel feed tube (B).
    G13834009Courtesy of KIA MOTORS AMERICA, INC.
    NOTE:
    • When removing the quick-connector with the clip removing tool, be careful not to damage the plastic clip (A).
      G13834010Courtesy of KIA MOTORS AMERICA, INC.
    • Damaged clip can result in fuel line leakage due to bad connection.
    • There may be some residual pressure even after completing "Release Residual Pressure in Fuel Line", so cover the hose connection with a shop towel to prevent residual fuel from spilling out before disconnecting any fuel connection.
  3. Install the special service tool (09353 - 24100, 09353 - 02100).
    G13834011Courtesy of KIA MOTORS AMERICA, INC.
  4. Measure fuel pressure.
    1. Start the engine and measure the fuel pressure at idle.

      Fuel Pressure: 

      4.8 - 5.2 bar (480 - 520 kPa, 4.9 - 5.3 kgf/cm2 , 69.6 - 75.4 psi)

      NOTE: If the fuel pressure differs from the standard value, repair or replace the related part (Refer to the table below).
      Fuel Pressure Cause Related Part
      Too Low Fuel filter clogged Fuel Filter
      Fuel leakage Fuel Pressure Regulator
      Too High Fuel pressure regulator valve stuck Fuel Pressure Regulator
    2. Stop the engine, and then check for the change in the fuel pressure gauge reading.

      Standard Value  : The gauge reading should hold for about 5 minutes after the engine stops

      NOTE: If the gauge reading should not be held, repair or replace the related part (Refer to the table below).
      Fuel Pressure (After Engine Stops) Cause Related Part
      Fuel Pressure Drops Slowly Leakage on injector Injector
      Fuel Pressure Drops Immediately Check valve of fuel pump stuck open Fuel Pump
    3. Turn the ignition OFF.
  5. Release the residual pressure in fuel line.

    (Refer to " RELEASE RESIDUAL PRESSURE  ") 

    NOTE:
    • When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the KDS after completion of "Release Residual Pressure in Fuel Line" work.
    • Connect the low pressure fuel feed tube and the low pressure inlet of high pressure fuel pump.
  6. Finish test.
    1. Remove the Special Service Tool (SST) from the low pressure fuel feed tube and the low pressure inlet of high pressure fuel pump.
    2. Connect the low pressure fuel feed tube and the low pressure inlet of high pressure fuel pump.
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