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No.29 Spark Plug Condition: Notes

POSSIBLE CAUSE & DESCRIPTION (SPARK PLUG CONDITION)

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
  • Compression-Low compression
  • Clogging in intake/exhaust system
Grayish white with all plugs: 
  • Air/fuel mixture-Too lean
WARNING: The following DIAGNOSTIC PROCEDURE TABLE  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 article.

    (See BEFORE SERVICE PRECAUTION .)

    (See AFTER SERVICE PRECAUTION .)

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.