Spark Plug: Testing and Inspection

Spark Plug Inspection




1. Inspect the electrodes and ceramic insulator.

Burned or worn electrodes may be caused by:
- Advanced ignition timing
- Loose spark plug
- Plug heat range too hot
- Insufficient cooling

Fouled plug may be caused by:
- Retarded ignition timing
- Oil in combustion chamber
- Incorrect spark plug gap
- Plug heat range too cold
- Excessive idling/low speed running
- Clogged air cleaner element
- Deteriorated ignition coils




2. Do not adjust the gap of platinum tip plugs (A); replace the spark plug if the gap is out of specification.

Electrode Gap:
Standard (New): 1.0 - 1.1 mm (0.039 - 0.043 in.)
Service Limit: 1.3 mm (0.015 in.)




3. Replace the plug at the specified interval, or if the center electrode is rounded (A). Use only the spark plugs listed below.

Spark Plugs:
NGK: PFR7G-11S
DENSO: PK22PR-L11S

4. Apply a small quantity of anti-seize compound to the plug threads, and screw the plugs into the cylinder head finger-tight. Then torque them to 25 N.m (2.5 kgf.m, 18 lbf.ft).