No. 28 Spark Plug Condition: Notes

NO. 28 SPARK PLUG CONDITION - SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION) DESCRIPTION AND POSSIBLE CAUSE

28	SPARK PLUG CONDITION
DESCRIPTION	Incorrect spark plug condition.
POSSIBLE CAUSE	NOTE: Inspecting the spark plug conditions can determine whether a 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 If a spark plug on a specific cylinder is damaged or corroded: Malfunction spark plug Damage or corrosion due to pre-ignition or knocking Wet/carbon is stuck on all plugs: Spark-Spark weak Air/fuel mixture-Too rich, excessive fuel line pressure Erratic signal to PCM ECT 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 Restriction in intake/exhaust system Grayish white with all plugs: Erratic signal to PCM ECT sensor or related circuit malfunction MAF sensor or related circuit malfunction A/F sensor or related circuit malfunction HO2S or related circuit malfunction Air/fuel mixture-Too lean, insufficient fuel line pressure 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 [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)] .) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)] .) CAUTION: Disconnecting/connecting the quick release connector without cleaning it cause damage to the fuel pipe and the quick release connector. Always clean the 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 the spark plug conditions can determine whether a 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

If a spark plug on a specific cylinder is damaged or corroded:

Malfunction spark plug
- Damage or corrosion due to pre-ignition or knocking

Wet/carbon is stuck on all plugs:

Spark-Spark weak
Air/fuel mixture-Too rich, excessive fuel line pressure
Erratic signal to PCM
- ECT 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
Restriction in intake/exhaust system

Grayish white with all plugs:

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

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 [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)] .) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)] .)

CAUTION:

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