No. 29 Spark Plug Condition: Notes

NO. 29 SPARK PLUG CONDITION REFERENCE CHART (MZI-3.7)

29	SPARK PLUG CONDITION
DESCRIPTION	Incorrect spark plug condition
POSSIBLE CAUSE	NOTE: Inspecting spark plugs condition can determine whether problem is related to a specific cylinder or possibly all cylinders. Wet/carbon stuck on specific plug: Spark-Weak, not visible Air/fuel mixture-Excessive fuel injection volume Compression-No compression, low compression Malfunction spark plug Grayish white with specific plug: Air/fuel mixture-Insufficient fuel injection volume Malfunction spark plug Wet/carbon is stuck on all plugs: Spark-Spark weak Air/fuel mixture-Too rich, excessive fuel line pressure Erratic signal to PCM CHT sensor or related circuit malfunction MAF sensor or related circuit malfunction A/F sensor or related circuit malfunction HO2S or related circuit malfunction Compression-Low compression Clogging in intake/exhaust system Grayish white with all plugs: Air/fuel mixture-Too lean, insufficient fuel line pressure Erratic signal to PCM CHT sensor or related circuit malfunction MAF sensor or related circuit malfunction A/F sensor or related circuit malfunction HO2S or related circuit malfunction WARNING: The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system: Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this service information. (See BEFORE SERVICE PRECAUTION article.) (See AFTER SERVICE PRECAUTION article.) CAUTION: Disconnecting/connecting quick release connector without cleaning it may cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

SPARK PLUG CONDITION

DESCRIPTION

Incorrect spark plug condition

POSSIBLE CAUSE

NOTE:

Inspecting spark plugs condition can determine whether problem is related to a specific cylinder or possibly all cylinders.

Wet/carbon stuck on specific plug:

Spark-Weak, not visible
Air/fuel mixture-Excessive fuel injection volume
Compression-No compression, low compression
Malfunction spark plug

Grayish white with specific plug:

Air/fuel mixture-Insufficient fuel injection volume
Malfunction spark plug

Wet/carbon is stuck on all plugs:

Spark-Spark weak
Air/fuel mixture-Too rich, excessive fuel line pressure
Erratic signal to PCM
- CHT sensor or related circuit malfunction
- MAF sensor or related circuit malfunction
- A/F sensor or related circuit malfunction
- HO2S or related circuit malfunction
Compression-Low compression
Clogging in intake/exhaust system

Grayish white with all plugs:

Air/fuel mixture-Too lean, insufficient fuel line pressure
Erratic signal to PCM
- CHT sensor or related circuit malfunction
- MAF sensor or related circuit malfunction
- A/F sensor or related circuit malfunction
- HO2S or related circuit malfunction

WARNING:

The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:

Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this service information.
(See BEFORE SERVICE PRECAUTION article.)

(See AFTER SERVICE PRECAUTION article.)

CAUTION:

Disconnecting/connecting quick release connector without cleaning it may cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.