Spark Plug: Testing and Inspection

ON-VEHICLE INSPECTION

NOTE: "Cold" and "Hot" in these sentences express the temperature of the coils and sensors themselves. "Cold" is from -10 °C (14 °F) to 50 °C (122 °F) and "Hot" is from 50 °C (122 °F) to 100 °C (212 °F).

1. INSPECT SPARK PLUGS

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

a. Remove the ignition coils and high-tension cord set assembly.




b. Inspect the electrode.
Using a merger (insulation resistance meter), measure the insulation resistance.

Standard correct insulation resistance: 10 MOhm or more
If the resistance is less than specified, proceed to step (d).

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




- Simple Method:
- Quickly race the engine 5 times to 4,000 rpm.
- Remove the spark plug. (See step c)
- Visually check the spark plug. If the electrode is dry. .0K
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 6 spark plugs.
d. Visually check the spark plug for thread damage and insulator damage.




If abnormal, replace the spark plug.




e. Inspect the electrode gap.
Maximum electrode gap for used spark plug: 1.2 mm (0.047 in.)
If the gap is greater than maximum, replace the spark plug.
Correct electrode gap for new spark plug: 1.0 - 1.1 mm (0.039 - 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 kgf/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, reinstall the 6 spark plugs.

Torque: 18 N.m (180 kgf.cm, 13 ft.lbf)

h. Reinstall the ignition coils and high-tension cord set assembly.