Mitsubishi 3000GT - Page 481

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ENGINE ELECTRICAL - Ignition System
16-35
OPERATION
l Turn ignition switch to .“ON”position, and battery
voltage will be applied to primary winding of
ignition coil.
l When crankshaft position sensor and camshaft
position sensor signal is input to engine control
module, engine control module makes ON-OFF
control of power transistors one by one.
l When power transistor is turned on, current
flows from ignition coil (primary winding) to
ground through power transistor.
l When power transistor A is turned from ON
to OFF, the spark plugs of No. 1 and No. 4
cylinders spark. Turning of power transistor B
from ON to OFF will produce sparking in spark
plugs of No. 2 and No. 5 cylinders. Furthermore,
when power transistor C is turned from ON to
OFF, sparking is produced in spark plugs of
No. 3 and No. 6 cylinders.
TROUBLESHOOTING HINTS
1. Engine cranks, but does not start.
(1) Spark is insufficient or does not occur at
all (on spark plug).
l Check ignition coil.
l Check camshaft position sensor and
crankshaft position sensor
l Check power transistor.
l Check spark plugs.
l Check spark plug cable.
(2) Spark is good.
l Check ignition timing.
2. Engine idles roughly or stalls.
l Check spark plugs.
l Check ignition timing.
l Check ignition coil.
l Check spark plug cable.
3. Poor acceleration
l Check ignition timing.
l Check spark plug cable.
l Check ignition coil.
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