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Ignition System: Inspection

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).

Check the electrode.
1. Using an ohmmeter, measure the insulation resistance.
  Correct insulation resistance: 10 MΩ or more
  
  If the resistance is below the specified range, go to procedure "A".
  
  HINT:
  
  If an ohmmeter is not available, the following simple inspection provides fairly accurate results.
  
  Fig 1: Measuring Insulation Resistance Using Ohmmeter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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.
Fig 2: Identifying Spark Plug
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the spark plug for thread or insulator damage (Procedure "B").

If damaged, replace the spark plug.

Recommended spark plug:

RECOMMENDED SPARK PLUG

DENSO made	NGK made
SK20R11	IFR6A11

Fig 3: Checking Spark Plug For Thread Or Insulator Damage (Procedure "B")

G04962919

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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.)

Fig 4: Measuring Spark Plug Electrode Gap (Procedure "A"
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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/cm ² , 85 psi)

Duration: 20 seconds or less

HINT:

If there are traces of oil, remove them with gasoline before using a spark plug cleaner.

Fig 5: Cleaning Spark Plugs
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT WT SENSOR
1. Using an ohmmeter, measure the resistance between the terminals.
  Resistance: Cold: 835 to 1,400 Ω
  
  Hot: 1,060 to 1,645 Ω
  
  NOTE: "Cold" and "Hot" above 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).
INSPECT CRANKSHAFT POSITION SENSOR
1. Using an ohmmeter, measure the resistance between the terminals.
  Resistance:
  
  Cold: 1,630 to 2,740 Ω
  
  Hot: 2,065 to 3,225 Ω
  
  NOTE: "Cold" and "Hot" above 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).