Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 545

13B-64
Wave Pattern Observation Points
Point: Condition of wave pattern build-up section and maximum voltage (Refer to abnormal wave pattern
examples 1 and 2.)
Condition of wave pattern build-up section and maximum voltage
Rises from approx. 2V to approx. 4.5V at the top-right
2V rectangular wave
Rectangular wave at power voltage
--- Normal wave pattern
2V
--- Normal wave pattern
V
B
MPI –
Troubleshooting
Probable cause
Normal
Open-circuit in ignition primary circuit
Power transistor malfunction
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 2V too low.
Example 2
Wave pattern during engine cranking
Cause of problem
Malfunction in power transistor
Wave pattern characteristics
Power voltage results when the power transistor is ON.