Mitsubishi MOTORS Lancer Evolution IX 2005, Workshop Manual Supplement

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13A-26 MPI – TROUBLESHOOTING
<Standard waveforms>
Observation conditions
Exhaust cam position sensor Crank angle sensor
Probe switch X1 x1
AC-GND-DC DC DC
TIME/DIV. 10ms 10 ms
VOLTS/DIV. 2V 2V
Other - -
Engine Idling
2 engine revolutions (1 camshaft revolution)
crank angle
sensor
output
waveform
exhaust cam
position sensor
output
waveform
Standard waveform
<Explanation of waveforms>
• The exhaust cam position sensor detects the compression top dead centre for each cylinder, and by simultaneous
observation of these and other controlling signals, it is possible to distinguish between the cylinders.
• The crank angle sensor detects the crank angle for each cylinder. There is an output of 4 evenly spaced crank angle sensor
HIGH signals for every 2 revolutions of the engine. Therefore, by measuring the cycle time (seconds), engine revolution
speed can calculated according to the following formula:
Engine revolution speed = 2/4T (seconds) x 60 = 30/T (seconds)
<Waveform observation points>
• Check that the cycle time gets shorter as the engine revolution speed increases.