Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2005 Lexus RX 330 AWDFACTORY OEM SERVICE PROCEDURE

Ignition System (3MZ-FE): Inspection

INSPECT SPARK PLUG

NOTE:

Do not use a wire brush for cleaning.
Do not attempt to adjust the electrode gap of a used spark plug.
Spark plug should be replaced every 200,000 km (120,000 miles).

Check the electrode.
1. Using a megaohmmeter, measure the insulation resistance.
  Correct insulation resistance: 10 MΩ or higher
  
  If the resistance is less then the specified value, proceed to step d.
  
  HINT:
  
  If the megaohmmeter is not available, do the following simple inspection instead.
  
  Fig 1: Measuring Insulation Resistance
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Alternative inspection Method:
1. Quickly accelerate the engine to 4,000 rpm 5 times.
2. Remove the spark plug.
3. Visually check the spark plug.
  
  Fig 2: Visually Checking Spark Plug
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. If the electrode is dry...OK.
5. If the electrode is wet...Proceed to step c.
6. Reinstall the spark plug.

Check the spark plug for any damage on its thread and insulator.

If there is damage, replace the spark plug.

Fig 3: Checking Spark Plug

G03011648

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Recommended spark plug:

SPARK PLUG CHART

DENSO made	SK20R11
NGK made	IFR6A11

Check the spark plug 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: 1.0 to 1.1 mm (0.039 to 0.043 in.)

Fig 4: Checking Spark Plug Electrode Gap
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Clean the spark plugs.
If the electrode has traces of wet carbon, clean the electrode with a spark plug cleaner then dry it.
- Air pressure: Blow 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 the spark plug cleaner.

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

INSPECT VVT SENSOR
1. Using an ohmmeter, measure the resistance between the terminals.
  RESISTANCE:
  - 835 to 1,400 Ω at cold
  - 1,060 to 1,645 Ω at hot
  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).
INSPECT CRANKSHAFT POSITION SENSOR
1. Using an ohmmeter, measure the resistance between the terminals.
  RESISTANCE:
  - 1,630 to 2,740 Ω at cold
  - 2,065 to 3,225 Ω at hot
  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).

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

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