Spark Plug Condition - Mazda RX-8 Manual

NO.29 SPARK PLUG CONDITION
29

SPARK PLUG CONDITION

Incorrect spark plug condition
DESCRIPTION
NOTE:
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POSSIBLE
CAUSE
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WARNING:
and repair procedures. Read the following warnings before servicing the fuel system:
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Inspecting the spark plugs condition can determine whether the problem is related to
a specific spark plug or possibly all spark plugs.
Wet/carbon stuck on specific plug:
SparkWeak, not visible
Air/fuel mixtureExcessive fuel injection volume
CompressionNo compression, low compression
Faulty spark plug
Grayish white with specific plug:
Air/fuel mixtureInsufficient fuel injection volume
Faulty 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
The following troubleshooting flow chart contains fuel system diagnosis
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 REPAIR PROCEDURE" and "AFTER REPAIR
PROCEDURE" described in this manual.
(See BEFORE REPAIR PROCEDURE .)
(w) RX8-Engine Troubleshooting
Page 143