Spark Plug Diagnosis


Failure

Cause

Consequences

Fig.

Improperly adjusted ignition system

Spark advance (from a proper moment)

Pre - ignitions Detonation burning

2

 

Spark delay (from a proper moment)

Excessive formation of combustion deposits

1

Improper air/fuel ratio

Rich mixture

Excessive formation of combustion deposits

1

 

Lean mixture

Pre - ignitions Detonation burning

2

Low or no performance of the air filter

Dust penetration into the combustion area

Excessive deposits

3

 

Filter impassability

Excessive formation of combustion deposits

1

Compression pressure

Low

Excessive formation of combustion deposits

1

Improperly selected spark plug

Too hot

Pre - ignitions Detonation burning

2

 

Too cold

Excessive formation of combustion deposits

1

None

 

Perfect performance of the spark plug

4