Ignition System: Inspection

NOTE: In the following step, the terms "cold" and "hot" refer to the temperature of the coils. "Cold" means approximately -10°C (14°F) to 50°C (122°F). "Hot" means approximately 50°C (122°F) to 100°C (212°F).

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.

Check the electrode.
1. Using an megaohmmeter, 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 megaohmmeter is not available, do the following simple inspection instead.
  
  Fig 1: Using Megaohmmeter To Measure Insulation Resistance
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Alternative inspection method:
1. Quickly accelerate the engine to 4,000 RPM 5 times.
2. Remove the spark plug.
3. Visually check the spark plug.
4. If the electrode is dry, the spark plug is functioning. Proceed to step 2.
5. If the electrode is damp, proceed to step ( c), ( d) and ( e).
6. Install the spark plug.

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

If there is any damage, replace the spark plug.

Recommended spark plug

SPARK PLUG SPECIFICATION

Manufacturer	Type
DENSO	SK20R11
NGK	IFR6A11

Fig 2: Checking Spark Plug For Any Damage On Its Thread And Insulator

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 the maximum, replace the spark plug.

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

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 on a used plug.

Fig 3: 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 and then dry it.

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

Duration: 20 seconds or less

HINT:

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

Fig 4: Cleaning Spark Plugs Using Spark Plug Cleaner
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002