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Home >> Toyota >> 2008 >> Sequoia Platinum, 4WD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (3UR-FE) - Circuit Testing, Component On-Vehicle Inspection, Removal, Inspection & Installation >> Ignition System >> On-Vehicle Inspection

On-Vehicle Inspection

  1. PERFORM SPARK TEST 
    1. Check for DTCs (See DIAGNOSTIC TROUBLE CODE CHART ).
      NOTE: If any DTC is present, perform troubleshooting procedures for that DTC.
    2. Check if sparks occur.
      1. Remove the ignition coils and spark plugs (See REMOVAL  ).
      2. Install the spark plug to the ignition coil and connect the ignition coil connector.
      3. Disconnect the 8 injector connectors.
      4. Ground the spark plug.
      5. Visually check that sparks occur while the engine is being cranked.
        NOTE:
        • Be sure to ground the spark plug when checking.
        • If the ignition coil has been struck or dropped, replace it.
        • Do not crank the engine for more than 2 seconds.
    3. Perform the spark test according to the procedures below:
      Fig 1: Checking That Sparks Occur While Engine Is Being Cranked
      G05644723Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check that the wire harness side connector of the ignition coil with igniter is securely connected.

        Result 

        RESULT REFERENCE

        Result Proceed to
        NG Connect securely
        OK Go to Next Step.
      2. Perform a spark test on each ignition coil with igniter.
        1. If there is a cylinder where sparks do not occur, replace its ignition coil with the ignition coil of a cylinder where sparks occur normally.
        2. Crank the engine and visually check that sparks occur at the cylinder with the normally operating ignition coil.

          Result 

          RESULT REFERENCE

          Result Proceed to
          OK Replace ignition coil with igniter
          NG Go to Next Step.
      3. Check spark plug.

        Result 

        RESULT REFERENCE

        Result Proceed to
        NG Replace spark plug
        OK Go to Next Step.
      4. Check the power supply to the ignition coil with igniter.
        1. Turn the ignition switch to ON.
        2. Check that there is battery voltage at the ignition coil positive (+) terminal.

          Result 

          RESULT REFERENCE

          Result Proceed to
          NG Check wiring between ignition switch and ignition coil with igniter
          OK Go to Next Step.
      5. Check the VVT sensor for intake camshaft (See DESCRIPTION ).
      6. Check the VVT sensor for exhaust camshaft (See DESCRIPTION ).
      7. Check the camshaft position sensor (See DESCRIPTION ).
      8. Check the crankshaft position sensor (See DESCRIPTION ).
      9. Check the IGT signal circuit (See DESCRIPTION ).
    4. Connect the 8 injector connectors.
    5. Install the ignition coils and spark plugs (See REMOVAL  ).
  2. INSPECT SPARK PLUG 
    NOTE:
    • Do not use a wire brush for cleaning.
    • Do not attempt to adjust the electrode gap of a used spark plug.
    1. Check the electrode.
      1. Using a megohmmeter, measure the resistance.

        Standard Resistance 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        Spark plug (terminal part) - Body ground Always 10 MΩ or higher

        If the insulation resistance is below the specified range, replace the spark plug.

        HINT:

        If a megohmmeter is not available, perform the following simple inspection instead.

    2. Alternative inspection method:
      1. Quickly accelerate the engine to 4000 rpm 5 times.
      2. Remove the spark plug.
        Fig 2: Checking Electrode
        G05644724Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Visually check the spark plug.

        If the electrode is dry, the spark plug is functioning properly. If the electrode is damp, proceed to the next step.

        Fig 3: Checking Spark Plug
        G05644725Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Check the spark plug for any damage to its threads and insulator.

      If there is any damage, replace the spark plug.

      Recommended Spark Plug 

      RECOMMENDED SPARK PLUG

      Manufacturer Type
      DENSO made SK20HR11

      HINT: 

      • Maximum electrode gap for a used spark plug: 1.3 mm (0.0512 in).
      • If the gap is greater than the maximum, replace the spark plug.
      • Electrode gap for a new spark plug: 1.0 to 1.1 mm (0.0394 to 0.0433 in).
        Fig 4: Checking Spark Plug Electrode Gap
        G05644726Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: If adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip. Never attempt to adjust the gap of a used plug.

      If the electrode has traces of wet carbon, allow it to dry and then clean it with a spark plug cleaner.

      Standard air pressure: 588 kPa (6.0 kgf/cm 2  , 85 psi) 

      Standard duration: 20 seconds or less 

      HINT:

      Only use the spark plug cleaner when the electrode is free of oil. If the electrode has traces of oil, use gasoline to clean off the oil before using the spark plug cleaner.

      Fig 5: Cleaning Spark Plug Electrode
      G05644727Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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