Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 190

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-459

CAMSHAFT POSITION SENSOR AND
CRANKSHAFT POSITION SENSOR

Required Special Tools:
MB991348: Test Harness
MD998478: Test Harness
Measurement Method
1. Disconnect the camshaft position sensor connector, and

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

2. Connect the oscilloscope probe to camshaft position sensor

connector terminal 5.

3. Disconnect the crankshaft position sensor connector, and

connect the test harness special tool (MD998478) in
between.

4. Connect the oscilloscope probe to crankshaft position

sensor connector terminal 2 (black clip of special tool).

Alternate method (Test harness not available)

<M/T>

1. Connect the oscilloscope probe to ECM terminal 50. (Check

the camshaft position sensor signal wave pattern.)

2. Connect the oscilloscope probe to ECM terminal 43. (Check

the crankshaft position sensor signal wave pattern.)

<A/T>

1. Connect the oscilloscope probe to PCM terminal 56. (Check

the camshaft position sensor signal wave pattern.)

2. Connect the oscilloscope probe to PCM terminal 45. (Check

the crankshaft position sensor signal wave pattern.)

Standard Wave Pattern

Observation conditions

Function

Special pattern

Pattern height

Low

Pattern selector

Display

Engine r/min

Idle speed

AK000061

1 2 3 4 5 6 7

OSCILLOSCOPE

CAMSHAFT POSITION
SENSOR CONNECTOR

OSCILLO-

SCOPE

PROBE

AB

AKX01500

CRANKSHAFT POSITION
SENSOR CONNECTOR

OSCILLOSCOPE

1 2

3

AB

OSCILLO-
SCOPE
PROBE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-460

Wave Pattern Observation Points

1. Check that cycle time T becomes shorter when the engine

speed increased.

Examples of Abnormal Wave Patterns
Example 1

•

Cause of problem
Sensor interface malfunction.

•

Wave pattern characteristics
Rectangular wave pattern is output even when the engine is
not started.

Example 2

•

Cause of problem
Loose timing belt.
Abnormality in sensor disc.

•

Wave pattern characteristics
Wave pattern is displaced to the left or right.

AKX01600

2 ENGINE REVOLUTIONS (1 CAMSHAFT REVOLUTION)

75

BTDC

5

BTDC

T

CYCLE TIME CHANGES
WITH ENGINE SPEED
CHANGES

CRANKSHAFT

POSITION

SENSOR OUTPUT

WAVE PATTERN

CAMSHAFT

POSITION

SENSOR OUTPUT

WAVE PATTERN

TDC: TOP DEAD CENTER

NO.1 TDC

NO.2 TDC

NO.3 TDC

NO.4 TDC

NO.5 TDC

NO.6 TDC

TIME

Standard wave pattern

AB

AKX01597

AKX01602

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-461

INJECTOR

Required Special Tools:
MB991348: Test Harness
MD998464: Test Harness
Measurement Method
<Measure at the right bank (number 1, 3, 5 cylinders)>

1. Disconnect the injector intermediate connector, and connect

the test harness special tool (MD998464) in between.

2. Connect the oscilloscope probe to each injector

intermediate connector terminal to analyze each cylinder:

•

Terminal 2 (black clip of special tool) for the number 1
cylinder

•

Terminal 3 (blue clip) for the number 3 cylinder

•

Terminal 4 (white clip) for the number 5 cylinder

<Measure at the right bank (number 2, 4, 6 cylinders)>

1. Disconnect the injector connector, and connect the test

harness special tool (MB991348) in between. (All terminals
should be connected.)

2. Connect the oscilloscope probe to injector connector

terminal 2.

Alternate method (Test harness not available)

1. Connect the oscilloscope probe to ECM <M/T> or PCM

<A/T> terminal 1. (When checking the number 1 cylinder.)

2. Connect the oscilloscope probe to ECM <M/T> or PCM

<A/T> terminal 9. (When checking the number 2 cylinder.)

3. Connect the oscilloscope probe to ECM <M/T> or PCM

<A/T> terminal 24. (When checking the number 3 cylinder.)

4. Connect the oscilloscope probe to ECM <M/T> or PCM

<A/T> terminal 2. (When checking the number 4 cylinder.)

5. Connect the oscilloscope probe to ECM <M/T> or PCM

<A/T> terminal 10. (When checking the number 5 cylinder.)

6. Connect the oscilloscope probe to ECM <M/T> or PCM

<A/T> terminal 25. (When checking the number 6 cylinder.)

Standard Wave Pattern

Observation conditions

Function

Special pattern

Pattern height

Variable

Variable knob

Adjust while viewing the wave pattern

Pattern selector

Display

Engine r/min

Idle speed

AK000063

1 2

3 4

OSCILLOSCOPE

INJECTOR INTERMEDIATE
CONNECTOR

OSCILLO

SCOPE

PROBE

AB

AK000587

OSCILLOSCOPE

OSCILLO

SCOPE

PROBE

1

2

AB

INJECTOR
CONNECTOR

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-462

Wave Pattern Observation Points
Point A: Height of injector coil induced voltage.

Point B: Injector drive time

1. The injector drive time should be synchronized with the

scan tool tester display.

2. When the engine is suddenly revved, the drive time will be

greatly extended at first, but the drive time will soon return
to original length.

IDLE AIR CONTROL MOTOR (STEPPER MOTOR)

Required Special Tool:
MB991709: Test Harness

CONTRAST WITH
STANDARD WAVE
PATTERN

PROBABLE CAUSE

Injector coil induced voltage is
low or doesn't appear at all

Short in the injector solenoid

AKX01604

(V)

50

0

DRIVE SIGNAL:"ON"

POINT B:
INJECTOR DRIVE
TIME

POINT A

DRIVE SIGNAL:"OFF"

POWER VOLTAGE

INJECTION COIL INDUCED
VOLTAGE (APPROXIMATELY 50-60 V)

AB

Standard wave pattern

AKX01605

WHEN IDLING

WHEN RACING

AB