Mitsubishi Montero Sport (2004+). Manual - part 99

 

  Index      Mitsubishi     Mitsubishi Montero Sport - service repair manual 2004 year

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  97  98  99  100   ..

 

 

Mitsubishi Montero Sport (2004+). Manual - part 99

 

 

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-37

Point B: 

Number of vibrations 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.

.

ABNORMAL WAVEFORMS EXAMPLES
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.

NUMBER OF VIBRATIONS

COIL AND CAPACITOR

Three or more

Normal

Except above

Abnormal

NUMBER OF VIBRATIONS

COIL

− 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

AKX00280

AKX00281

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-38

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 wave 
pattern example 1.

• Cause of problem

Spark plug cable is not properly connected. (Causing a 
dual ignition)

Example 5

• Wave characteristics

No waves in wave damping section

• Cause of problem

Layer short in ignition coil.

AKX00282

AKX00283

AKX00284

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-39

IGNITION PRIMARY VOLTAGE WAVE PATTERN 
CHECK USING AN OSCILLOSCOPE

M1163004600105

.

MEASUREMENT METHOD

Required Special Tool:
MB991348: Test Harness Set
1. Disconnect the ignition power transistor connector and 

connect the test harness set of the special tool (MB991348) 
in between. All terminals should be connected.

2. When observing the number 1 

− 4 cylinder group, connect 

the primary pickup of the oscilloscope probe to ignition 
power transistor side connector terminal (13).
For the number 2 

− 5 cylinder group, connect to terminal 

(12) and for the number 3 

− 6 cylinder group, connect to 

terminal (11).

3. Ground the primary pickup ground terminal.
4. Clamp the spark plug cable with the trigger pickup.

NOTE: Clamp the spark plug cable of cylinder number 1, 3 
or 5 which belongs to the same group as the cylinder to 
which the primary pickup is connected.
NOTE: The wave pattern of any cylinder in the same group 
appears from the left side of the screen.

.

STANDARD WAVE PATTERN

Observation conditions

FUNCTION

SECONDARY

Pattern height

High (or low)

Pattern selector

Raster

Engine speed

Curb idle speed

AKX00285

11 12 13

PRIMARY
PICKUP

OSCILLOSCOPE

AB

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-40

Observation conditions (Only pattern selector below 
changes from the above conditions.)

Pattern selector

Display

AKX00286

PRIMARY
VOLTAGE
WAVE PATTERN

(V)

100

0

ZENER
VOLTAGE
(POINT C)

(APPROXIMATELY
40 

× 10 V)

DWELL SECTION

SPARK LINE
(POINT A)

WAVE DAMEPING REDUCTION
SECTION (POINT B)

TIME

AB

 

 

 

 

 

 

 

Content   ..  97  98  99  100   ..