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Home >> Lexus >> 2004 >> IS 300 Base, Standard >> Repair and Diagnosis >> Engine Mechanical >> Fuel System >> SFI >> Fuel Pump >> On-Vehicle Inspection

On-Vehicle Inspection

  1. CHECK FUEL PUMP OPERATION 
    1. Connect a hand-held tester to the DLC3.
      2. Fig 1: Connecting Hand-Held Tester To DLC3
      G00893868Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the ignition switch ON and hand-held tester main switch ON.
      NOTE: Do not start the engine. 
    3. Select the ACTIVE TEST mode on the hand-held tester.
    4. Please refer to the hand-held tester operator's manual for further details.
    5. If you have no hand-held tester, connect the positive (+) and negative (-) leads from the battery to the fuel pump connector (See step  3).
    6. Check that the pulsation damper screw rises up when the fuel pump operates.

      If there is no pressure, check the fusible link, fuses, EFI main relay, fuel pump ECU, fuel pump, ECM and wiring connections.

      7. Fig 2: Identifying Pulsation Damper Screw
      G00893869Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Turn the ignition switch OFF.
    8. Disconnect the hand-held tester from the DLC3.
  2. CHECK FUEL PRESSURE 
    1. Check the battery positive voltage is above 12 V.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Remove the union bolt and 2 gaskets, and disconnect the fuel inlet hose from the fuel pipe support.
      Fig 3: Disconnecting Fuel Inlet Hose From Fuel Pipe Support
      G00893870Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE:
      • Put a shop towel under the fuel pipe support. 
      • Slowly loosen the union bolt. 
    4. Install the fuel inlet house and SST (pressure gauge) to the fuel pipe support with the 3 gaskets and SST (union and adapter).
      Fig 4: Installing Fuel Inlet House & SST (Pressure Gauge) To Fuel Pipe Support
      G00893871Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. SST 09268-45014 (09268-41190, 90405-06167)
      2. Torque: 29 N.m (300 kgf.cm, 21 ft.lbf) 
    5. Wipe off any splattered gasoline.
    6. Connect a hand-held tester to the DLC3 (See step  1 in check fuel pump operation (a) to (e).
    7. Measure the fuel pressure.
      Fig 5: Connecting Hand-Held Tester To DLC3
      G00893872Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Fuel pressure: 304 - 343 kPa (3.1 - 3.5 kgf/cm 2  , 44 - 50 psi) 

      If pressure is high, replace the fuel pressure regulator. If pressure is low, check the fuel hoses and connections, fuel pump, fuel filter and fuel pressure regulator.

    8. Disconnect the hand-held tester from the DLC3.
    9. Start the engine.
    10. Measure the fuel pressure at idle.
      1. Fuel pressure: 304 - 343 kPa (3.1 - 3.5 kgf/cm 2  , 44 - 50 psi) 
    11. Stop the engine.
    12. Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.
      1. Fuel pressure: 147 kPa (1.5 kgf/cm 2  , 21 psi) or more 

      If pressure is not as specified, check the fuel pump, pressure regulator and/or injectors.

    13. After checking fuel pressure, disconnect the negative (-) terminal cable from the battery and carefully remove SST to prevent gasoline from splashing.
      1. SST 09268-45014
    14. Reconnect the fuel inlet hose to the fuel pipe support with 2 new gaskets and the union bolt.
      1. Torque: 29 N.m (300 kgf.cm, 21 ft.lbf) 
    15. Reconnect the negative (-) terminal cable to the battery.
    16. Check for fuel leaks.
  3. INSPECT FUEL PUMP 
    1. Remove the rear seat cushion.
    2. Remove the 3 cap nuts and floor service hole cover.
    3. Disconnect the fuel pump & sender gauge connector.
    4. Using an ohmmeter, measure the resistance between terminals 4 and 5.
      1. Resistance: 0.2 - 3.0 Ω at 20°C (68°F) 
      Fig 6: Measuring Resistance Between Terminals 4 & 5 Of Fuel Pump Connector
      G00893873Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      If the resistance is not as specified, replace the fuel pump.

    5. Inspect the fuel pump operation.
      Fig 7: Inspecting Fuel Pump Operation
      G00893874Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Connect the positive (+) lead from the battery to terminal 4 of the connector, and the negative (-) lead to terminal 5. Check that the fuel pump operates.

      NOTE:
      • These tests must be done quickly (within 10 seconds) to prevent the coil burning out. 
      • Keep the fuel pump as far away from the battery as possible. 
      • Always do the switching at the battery side. 

      If operation is not as specified, replace the fuel pump.

    6. Reconnect the fuel pump & sender gauge connector.
    7. Reinstall the floor service hole cover with the cap nuts.
    8. Reinstall the rear seat cushion.
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