FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Spark Plug: Testing and Inspection



NOTICE:
- Never use a wire brush 1cr 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).

1. DISCONNECT HIGH-TENSION CORDS FROM SPARK PLUGS.





2. INSPECT ELECTRODE
- Using a megger (insulation resistance meter), measure the insulation resistance.

Standard correct insulation resistance: 10 M Ohms or more

- If the resistance is less than specified, proceed to step 3.

HINT: If a megger 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 3)
- Visually check the spark plug.
- If the electrode is dry...OK
- If the electrode is wet...Proceed to step 4
- Reinstall the spark plug. (See step 7)
3. REMOVE SPARK PLUGS
- Using a 16 mm plug wrench, remove the 6 spark plugs.
4. VISUALLY INSPECT SPARK PLUGS
- Check the spark plug for thread damage and insulator damage.
- If abnormal, replace the spark plug.

Recommended spark plug:
ND: PK16R11
NGK: BKR5EP11






5. INSPECT 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: 1.1 mm (0.043 in.)

NOTICE:
- 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.





6. CLEAN 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 (8 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.

7. REINSTALL SPARK PLUGS

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

8. RECONNECT HIGH-TENSION CORDS TO SPARK PLUGS