Spark Plug: Testing and Inspection
INSPECTION1. INSPECT SPARK PLUG
NOTE:
- Never use a wire brush for cleaning.
- Never attempt to adjust the electrode gap on a used spark plug.
- The spark plug should be replaced every 200,000 km (120,000 miles).
a. Check the electrode.
1. Using an ohmmeter, measure the insulation resistance. Correct insulation resistance: 10 mohms or more
If the resistance is the specified range, go to procedure "A".
HINT: If an ohmmeter is not available, the following simple inspection provides fairly accurate results.
b. Simple Method:
1. Quickly race the engine to 4,000 rpm 5 times.
2. Remove the spark plug.
3. Visually check the spark plug.
4. If the electrode is dry... OK.
5. If the electrode is wet... Go to procedure "B".
6. Reinstall the spark plug.
c. Check the spark plug for thread or insulator damage (Procedure "B").
If damaged, replace the spark plug. Recommended spark plug:
d. Measure the spark plug electrode gap (Procedure "A")
Maximum electrode gap for used spark plug: 1.3 mm (0.051 in.)
If the gap is greater than the maximum, replace the spark plug.
Correct electrode gap for new spark plug: 1.0 to 1.1 mm (0.039 to 0.043 in.)
e. 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 them with gasoline before using a spark plug cleaner.
2. INSPECT VVT SENSOR
a. Using an ohmmeter, measure the resistance between the terminals.
Resistance:
Cold: 835 to 1,400 ohms
Hot: 1,060 to 1,645 ohms
NOTE:� "Cold" and "Hot" mean the temperature of the coils 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).
3. INSPECT CRANKSHAFT POSITION SENSOR
a. Using an ohmmeter, measure the resistance between the terminals.
Resistance: Cold: 1,630 to 2,740ohms Hot: 2,065 to 3,225ohms
NOTE: "Cold" and "Hot" mean the temperature of the coils 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).