Spark Plug Inspection

1. Inspect the electrodes and ceramic insulator for:

Burned or worn electrodes may be caused by:
•   Advanced ignition timing
•   Loose spark plug
•   Plug heat range too low
•   Insufficient cooling
Fouled plug may be caused by:
•   Retarded ignition timing
•   Oil in combustion chamber
•   Incorrect spark plug gap
•   Plug heat range too high
•   Excessive idling/low speed running
•   Clogged air cleaner element
•   Deteriorated ignition coil or ignition wires
2. Adjust the gap with a suitable gapping tool. Electrode Gap: 1.1 mm (0.043 in)


3. Replace the plug if the center electrode is rounded as shown below:

NOTE: Do not use spark plugs other than those listed below, because these plugs are a new type (ISO standard).

Spark Plug D15B8/D15Z1 engine:
ZFR4F-11 (NGK) KJ14CR-L11 (Nippondenso)	For all normal driving.
ZFR5F-1 1 (NGK) KJ16CR-L11 (Nippondenso)	For hot climates or continuous high speed driving.
D15137 engine:
ZFR5F-11 (NGK) KJ16CR-L11 (Nippondenso)	For all normal driving.
ZFR6F-1 1 (NGK) KJ20CR-L11 (Nippondenso)	For hot climates or continuous high speed driving.
D16Z6 engine:
ZFR5J-11 (NGK) KJ16CR-L11 (Nippondenso)	For all normal driving.
ZFR6J-1 1 (NGK) KJ20CR-L11 (Nippondenso)	For hot climates or continuous high speed driving.

4. Screw the plugs into the cylinder head finger tight,
then torque them to 18 N•m (1.8 kg-m, 13 lb-ft).

NOTE: Apply a small quantity of anti-seize compound to the plug threads before installing.