Mitsubishi Eclipse. Manual - part 674

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-39

CAUTION

This test must be performed quickly (in less than 10 sec-
onds) to prevent coil from burning and ignition power tran-
sistor from breaking.
As described in the chart below, perform a continuity check on 
the ignition coil power transistor. Replace the ignition power 
transistor if there is a malfunction.

SPARK PLUG CABLE RESISTANCE CHECK

M1163001400094

Measure the resistance of the all spark plug leads.
1. Check the cap and coating for cracks.
2. Measure the resistance.

Limit: 19 k

Ω

SPARK PLUG TEST

M1163001500091

<3.0L ENGINE>

1. Remove the spark plug and connect to the spark plug cable.
2. Ground the spark plug outer electrode (body), and crank the 

engine.
Check that there is an electrical discharge between the 
electrodes at this time.

1.5 V POWER SUPPLY
BETWEEN 3 

− 4

CONTINUITY BETWEEN 
2 

− 4

Current flowing

Yes

Current not flowing

No

AKX00382

AKX00432

SPARK PLUG

AB

AKX00277

DEFECTIVE INSULATION

DEFECTIVE INSULATION

DEFECTIVE
INSULATION

GOOD

AB

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-40

SPARK PLUG CHECK AND CLEANING

M1163004300320

 <3.0L ENGINE>

CAUTION

• Do not attempt to adjust the gap of the iridium plug.
• Cleaning of the iridium plug may result in damage to 

the iridium tip. Therefore, if carbon deposits must be 
removed, use a plug cleaner and complete cleaning 
within 20 seconds to protect the electrode. Do not use a 
wire brush.

Check the plug gap and replace if the limit is exceeded.

Standard value: 0.7 

− 0.8 mm (0.028 − 0.031 inch)

Limit: 1.0 mm (0.039 inch)

CAMSHAFT POSITION SENSOR CHECK

M1163004400189

 <2.4L ENGINE>

Refer to GROUP 13A, Multiport Fuel Injection (MFI) <2.4L> 

− 

Multiport Fuel Injection (MFI) Diagnosis 

− Diagnostic Trouble 

Code Procedures 

− Camshaft Position Sensor Circuit Malfunc-

tion 

P.13A-431

.

CRANKSHAFT POSITION SENSOR CHECK

M1163004500238

<2.4L ENGINE>

Refer to GROUP 13A, Multiport Fuel Injection (MFI) <2.4L> 

− 

Multiport Fuel Injection (MFI) Diagnosis 

− Diagnostic Trouble 

Code Procedures 

− DTC P0335 : Crankshaft Position Sensor 

Circuit 

P.13A-409

.

CRANKSHAFT POSITION SENSOR CHECK

M1163004500249

<3.0L ENGINE>

Refer to GROUP 13B, Multiport Fuel Injection (MFI) <3.0L> 

− 

Multiport Fuel Injection (MFI) Diagnosis 

− Diagnostic Trouble 

Code Procedures 

− DTC P0335 : Crankshaft Position Sensor 

Circuit 

P.13B-557

.

IGNITION SECONDARY VOLTAGE WAVE 
PATTERN CHECK USING AN OSCILLOSCOPE

M1163001700192

<2.4L ENGINE>

.

MEASUREMENT METHOD
1. Clamp the spark plug cable (Number 1 or 3) with the 

secondary pickup.
NOTE: Because of the two-cylinder simultaneous ignition 
system, the waves for two cylinders in each group appear 
during wave observation. However, wave observation is car-
ried out for the cylinder (Number 1 or 3) with the spark plug 
cable which has been clamped by the secondary pickup.

AKX00383

AKX00383

IRIDIUM TIP

AK

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-41

NOTE:  Identification of which cylinder wave pattern is dis-
played can be difficult, but the wave pattern of the cylinder 
which is clamped by the secondary pickup will be stable, so 
this can be used as a reference.

2. Clamp the spark plug cable (Number 1 or 3) with the trigger 

pickup.
NOTE: Clamp the same spark plug cable as the one which 
has been clamped by the secondary pickup.

.

STANDARD WAVE PATTERN

Observation Conditions 

FUNCTION

SECONDARY

Pattern height

High (or low)

Pattern selector

Raster

Engine speed

Curb idle speed

AKX00278

kV

0

SECONDARY

IGNITION

VOLTAGE

WAVE PATTERN

IGNITION VOLTAGE
(POINT D)

SPARK LINE (POINT A)

DWELL SECTION

WAVE DAMPING REDUCTION SECTION (POINT B)

POINT C

TIME

AB

IGNITION SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-42

.

WAVEFORM OBSERVATION POINTS
NOTE:  Abnormal waveform examples are shown subse-
quently.
Point A: 

The height, length and slope of the spark line (refer to 
abnormal waveform examples 1, 2, 3 and 4) show the fol-
lowing trends.

Point B: 

Number of vibrations in reduction vibration section (Refer to 
Abnormal Waveform Example 5)

Point C: 

Observation Conditions 

Pattern selector

Display

Pattern height

High (or low)

Engine speed

Curb idle speed

AKX01275

kV

SECONDARY IGNITION
VOLTAGE 
WAVE 
PATTERN

0

2

NO. 1 CYLINDER

NO. 3 CYLINDER
IGNITION NOISE

NEUTRAL SECTION

NO. 4 CYLINDER

NO. 2 CYLINDER 
IGNITION NOISE

TIME

AB

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

Length Short

Large

Large wear

High

Lean

Retarded

High 
resistance

Height High

Large

Large wear

High

Lean

Retarded

High 
resistance

Height Low

Small

Normal

Low

Rich

Advanced

Leak

Slope

Large

Plug is fouled −

−

−

−

NUMBER OF VIBRATIONS

COIL AND CAPACITOR

Three or more

Normal

Except above

Abnormal