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Spark Plug: Inspection: Procedure

  1. SPECIFICATION 

    Spark plug type

    P51R-18-110

  2. INSPECT PLUG GAP 
    NOTE:
    • To avoid possible damage to the tip, do not adjust the plug gap.
    • To prevent damaging the tip, use a wire type plug gap gauge when inspecting the plug gap.
    1. Measure the spark plug gap using a wire type plug gap gauge.

      If not within the standard specification, replace the spark plug.

      Spark plug gap

      Standard: 1.05 to 1.40 mm (0.0414 to 0.0551 in.)

      New spark plug (reference): 1.05 to 1.15 mm (0.0414 to 0.0452 in.)

  3. CLEANING 
    NOTE:
    • Carbon may adhere to the tip of the spark plug during vehicle delivery or repeated short distance driving during the winter time. If there is any malfunction such as rough idling or start difficulty due to carbon adhesion causing plug fouling, burn off the carbon by performing no-load racing of the engine.
    • When performing the no-load racing, apply the side brake and foot brake, move the shift lever to neutral (MTX), or the selector lever to P position (ATX) to prevent an accident and serious injury.
    • To avoid possible damage to the spark plug tip, do not use a wire brush for cleaning.

    HINT: 

    • To avoid possible damage to the tip, use gasoline to clean the spark plugs after removing dirt.
    • If the accelerator pedal is depressed continuously for a specified time, the engine speed may decrease to the idle speed. This is due to the PCM control operation, which prevents overheating, and it does not indicate a malfunction.
    • Do not perform no-load racing at high engine speed continuously for 10 s or more.
    1. If there is carbon adhering to the spark plug, perform no-load racing at 4, 000 rpm for 2 min, 2 times.
  4. INSPECT VISUAL 
    1. Inspect the following items:
      GTY493422Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Burns
      *b Wear and Carbon Deposits
      *c Breakage
      *d Damage
      1. If any of the following malfunctions are indicated, replace the spark plug.
        • Insulator breakage
        • Worn electrode
        • Damaged gasket
        • Badly burned insulator (sparking side)
  5. INSPECT RESISTANCE 
    1. Measure the resistance of the spark plug using a ohmmeter as shown in the figure.

      If not within specification, replace the spark plug.

      Spark plug resistance [25°C (77 °F)]

      3.0 to 7.5 kilohms

      GTY488578Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002