Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1087

16-32
WAVEFORM OBSERVATION POINTS
Point A: The height, length and slope of the spark line show the following trends (Refer to abnormal
waveform examples, 1, 2, 3 and 4).
Spark line Plug gap
Length Long Small
Short Large
Height High Large
Low Small
Slope Large
Point B: Number of vibration in reduction vibration section (Refer to abnormal waveform example 5)
Number of vibrations
Three or more
Except above
Point C: Number of vibrations at beginning of dwell section (Refer to abnormal waveform example 5)
Number of vibrations
5 - 6 or higher
Except above
Point D: Ignition voltage height (distribution per each cylinder) shows the following trends.
Ignition Plug gap
voltage
High Large
Low Small
ENGINE ELECTRICAL -
Condition of Compression
electrode force
Normal Low
Large wear High
Large wear High
Normal Low
Plug is fouled -
Coil and condenser
Normal
Abnormal
Coil
Normal
Abnormal
Condition of Compression
electrode force
Large wear High
Normal Low
Ignition System
Concentration of Ignition timing
air mixture
Rich Advanced
Lean Retarded
Lean Retarded
Rich Advanced
- -
Concentration of Ignition timing
air mixture
Lean Retarded
Rich Advanced
Spark plug
cable
Leak
High
resistance
High
resistance
Leak
-
Spark plug cable
High resistance
Leak