Mitsubishi Lancer Evolution 7. Manual - part 233

ENGINE ELECTRICAL -

Ignition System

16-31

STANDARD WAVEFORM
Observation Conditions

Function

Secondary

Pattern height

High (or Low)

Pattern selector

Raster

Engine revolutions

Curb idle speed

kV

Secondary

ignition

voltage

waveform

Ignition voltage

(point D)

Dwell

section

Point C

Spark line (point A)

Wave damping

reduction section

(point B)

Time

Observation Condition (The only change from above condition is the pattern selector.)

Pattern selector

Display

Secondary

ignition

voltage

waveform

kV

No. 4 cylinder

No. 2 cylinder

ignition noise

No. 1 cylinder

No. 3 cylinder

ignition noise

Neutral section

0

2

Time

ENGINE ELECTRICAL -

Ignition System

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

Condition of

electrode

Compression

force

Concentration of

air mixture

Ignition timing

Spark plug

cable

Length

Long

Small

Normal

Low

Rich

Advanced

Leak

Short

Large

Large wear

High

Lean

Retarded

High

resistance

Height

High

Large

Large wear

High

Lean

Retarded

High

resistance

Low

Small

Normal

Low

Rich

Advanced

Leak

Slope

Large

Plug is fouled

-

-

-

-

Point B: Number of vibration in reduction vibration section (Refer to abnormal waveform example 5)

Number of vibrations

Coil and condenser

Three or more

Normal

Except above

Abnormal

Point C: Number of vibrations at beginning of dwell section (Refer to abnormal waveform example 5)

Number of vibrations

Coil

5 - 6 or higher

Normal

Except above

Abnormal

Point D: Ignition voltage height (distribution per each cylinder) shows the following trends.

Ignition

voltage

Plug gap

Condition of

electrode

Compression

force

Concentration of

air mixture

Ignition timing

Spark plug cable

High

Large

Large wear

High

Lean

Retarded

High resistance

Low

Small

Normal

Low

Rich

Advanced

Leak

ENGINE ELECTRICAL -

Ignition System

16-33

EXAMPLES OF ABNORMAL WAVEFORMS

Abnormal waveform

Wave characteristics

Cause of problem

Example 1

01P0215

Spark line is high and short.

Spark plug gap is too large.

Example 2

Spark line is low and long, and is

sloping.

Also, the second half of the spark line

is distorted. This could be a result of

misfiring.

Spark plug gap is too small.

Example 3

Spark line is low and long, and is

sloping. However, there is almost no

spark line distortion.

Spark plug gap is fouled.

Example 4

Spark line is high and short.

Difficult to distinguish between this

and abnormal waveform example 1.

Spark plug cable is nearly falling off.

(Causing a dual ignition)

Example 5

No waves in wave damping section.

Layer short in ignition coil

ENGINE ELECTRICAL -

Ignition System

16-34

IGNITION COIL

REMOVAL AND INSTALLATION

Pre-removal and Post-installation Operation

Center Cover Removal and Installation (Refer to GROUP 11A - Camshaft and Camshaft Oil Seal.)

10 ± 2 N·m

1

2

25 ± 4 N·m

3

4

1

4

5

10 ± 2 N·m

Removal steps

1. Ignition coil connector

2. Spark plug cable No.1

3. Spark plug cable No.3

4. Ignition coil

5. Spark plug