Mitsubishi Outlander (2003+). Manual — part 143

IGNITION SYSTEM

ENGINE ELECTRICAL

16-37

STANDARD WAVEFORM

Observation Conditions

Function

Secondary

Pattern height

High (or Low)

Pattern selector

Raster

Engine revolutions

Curb idle speed

AKX00278

kV

0

Secondary

ignition voltage

wave pattern

Ignition voltage
(point D)

Spark line (point A)

Dwell section

Wave dampling reduction section (point B)

Point C

Time

AD

IGNITION SYSTEM

ENGINE ELECTRICAL

16-38

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

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).

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

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

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

Pattern selector

Display

AKX01275

kV

Secondary ignition
voltage wave pattern

0

2

NO. 1 cylinder

NO. 3 cylinder
ignition noise

Newtral section

NO. 4 cylinder

NO. 2 cylinder
ignition noise

Time

AC

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

−

−

−

−

Number of vibrations

Coil and condenser

3 or more

Normal

Except above

Abnormal

Number of vibrations

Coil

5

−

6 or higher

Normal

Except above

Abnormal

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

IGNITION SYSTEM

ENGINE ELECTRICAL

16-39

EXAMPLES OF ABNORMAL
WAVEFORMS

Example 1

•

Wave characteristics
Spark line is high and short.

•

Cause of problem
Spark plug gap is too large.

Example 2

•

Wave characteristics
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.

•

Cause of problem
Spark plug gap is too small.

Example 3

•

Wave characteristics
Spark line is low and long, and is sloping.

However, there is almost no spark line
distortion.

•

Cause of problem
Spark plug gap is fouled.

Example 4

•

Wave characteristics
Spark line is high and short.
Difficult to distinguish between this and abnormal

waveform example 1.

•

Cause of problem
Spark plug cable is nearly falling off (Causing a

dual ignition).

Example 5

•

Wave characteristics
No waves in wave damping section.

•

Cause of problem
Layer short in ignition coil.

AKX00280

AKX00281

AKX00282

AKX00283

AKX00284

IGNITION SYSTEM

ENGINE ELECTRICAL

16-40

IGNITION COIL

REMOVAL AND INSTALLATION <4G63>

M1163004000493

AC301786

10 ± 2 N·m

25 ± 4 N·m

5

4

2

2

3

3

4

AB

1

3.0 ± 0.5 N·m

Removal steps

1.

Rocker cover centre cover

2.

Ignition coil connector

3.

Spark plug cable

4.

Ignition coil

5.

Spark plug

Removal steps (Continued)