Mitsubishi Eclipse. Manual - part 638
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.0L>
13B-1095
.
Examples of Abnormal Wave Patterns
Example 1 (Wave pattern during engine cranking)
• Cause of problem
Open-circuit in ignition primary circuit
• Wave pattern characteristics
Top-right part of the build-up section cannot be seen, and
voltage value is approximately 2 volts too low.
Example 2 (Wave pattern during engine cranking)
• Cause of problem
Malfunction in ignition power transistor
• Wave pattern characteristics
Power voltage results when the ignition power transistor is
ON.
CONDITION OF WAVE PATTERN
BUILD-UP SECTION AND
MAXIMUM VOLTAGE
PROBABLE CAUSE
Rises from approximate 2 volts to
approximate 4.5 volts at the top-right
Normal
2-volt rectangular wave
Open-circuit in ignition
primary circuit
Rectangular wave at power voltage
Ignition power
transistor malfunction
AKX01612
NORMAL WAVE
PATTERN
2V
AB
AKX01613
BATTERY
POSITION
VOLTAGE
NORMAL WAVE
PATTERN
AB