Spark Plug: Testing and Inspection

INSPECT SPARK PLUGS

NOTE:
- Never use a wire brush for cleaning.
- Never attempt to adjust the electrode gap on a used spark plug.
- Spark plugs should be replaced every 100,000 km (60,000 miles).

a. Disconnect the high-tension cords from the spark plugs.
b. Inspect the electrode.




Using a megger (insulation resistance meter), measure the insulation resistance.
- Standard correct Insulation resistance: 10 M Ohm or more
- If the resistance is less than specified, proceed to step (d).

HINT: If a megger is not available, the following simple method of inspection provides fairly accurate results.




Simple Method:
- Quickly race the engine to 4,000 rpm 5 times.
- Remove the spark plug. (See step (c))
- Visually check the spark plug.
- If the electrode is dry ..... OK
- If the electrode is wet... Proceed to step (d)
- Reinstall the spark plug. (See step (g))




c. Using a 16 mm plug wrench, remove the 4 spark plugs.
d. Visually check the spark plug for thread damage and insulator damage.
- If abnormal, replace the spark plug.

Recommended spark plug: DENSO made PK20TR11
NGK made BKR6EKPB11




e. Inspect the electrode gaps.
- 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: 1.1 mm (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 the used plug.




f. Clean the spark plugs.
- If the electrode has traces of wet carbon, allow it to dry and then clean with a spark plug cleaner.
Air pressure: Below 588 kPa (6 kg/sq.cm, 85 psi)
Duration: 20 seconds or less

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

g. Using a 16 mm plug wrench, install the 4 spark plugs.
- Torque: 18 Nm (180 kg.cm, 13 ft.lb)
h. Reconnect the high-tension cords from the spark plugs.