Ignition System: Inspection

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.
Spark plug should be replaced every 200,000 km (120,000 miles).

Check the electrode.
1. Using an ohmmeter, measure the insulation resistance.
  Correct insulation resistance: 10 MΩ or more
  
  If the resistance is less than the specified value, proceed to step ( d).
  
  HINT:
  
  If the ohmmeter is not available, do the following simple inspection instead.
  
  Fig 1: Measuring Insulation Resistance Using Ohmmeter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Simple inspection method:
1. Run the engine to 4,000 rpm 5 times quickly.
2. Remove the spark plug.
3. Visually check the spark plug.
4. If the electrode is dry... OK.
5. If the electrode is wet... Proceed to step (C).
6. Reinstall the spark plug.
Fig 2: Identifying Spark Plug
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the spark plug for any damage on its thread and insulator.

If there is damage, replace the spark plug.

Recommended spark plug:

SPARK PLUG SPECIFICATION

DENSO made	SK20R11
NGK made	IFR6A11

Fig 3: Checking Spark Plug For Damage On Thread And Insulator

G04494552

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

(d) Check the spark plug electrode gap.
Maximum electrode gap for used spark plug: 1.3 mm (0.051 in.)

If the gap is greater than maximum, replace the spark plug.

Correct electrode gap for new spark plug: 1.0 to 1.1 mm (0.039 to 0.043 in.)

Fig 4: Checking Spark Plug Electrode Gap
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Clean the spark plugs.
If the electrode has traces of wet carbon, clean the electrode with a spark plug cleaner, then dry it.

Air pressure: Blow 588 kPa (6 kgf/cm ² , 85 psi)

Duration: 20 seconds or less

HINT:

If there are traces of oil, remove it with gasoline before using the spark plug cleaner.

Fig 5: Cleaning Electrode With Spark Plug Cleaner
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002