Ignition System; General; Outline Of Change; General Information - Mitsubishi MOTORS L200 1996 Workshop Manual

16-2

IGNITION SYSTEM

GENERAL

OUTLINE OF CHANGE

The following service procedures have been
established to correspond to the change of the

GENERAL INFORMATION

This system is provided with two ignition coils (A
and B) and two power transistors (A and B) for
the No. 1 and No. 4 cylinders, and No. 2 and No.
3 cylinders respectively.
Interruption of the primary current flowing in the
primary side of ignition coil A generates a high
voltage in the secondary side of ignition coil A.
The high voltage thus generated is applied to the
spark plugs of No. 1 and No. 4 cylinders to generate
sparks. At the time that the sparks are generated
at both spark plugs, if one cylinder is at the
compression stroke, the other cylinder is at the
exhaust stroke, so that ignition of the compressed
air/fuel mixture occurs only for the cylinder which
is at the compression stroke.
In the same way, when the primary current flowing
in ignition coil B is interrupted, the high voltage
thus generated is applied to the spark plugs of
No. 2 and No. 3 cylinders.
Air flow sensor
Intake air temperature sensor
Barometric pressure sensor
Engine coolant temperature sensor
Idle position switch
Camshaft position sensor
Crank angle sensor
Vehicle speed sensor
Ignition switch-ST
ENGINE ELECTRICAL –
Power transistor unit
Engine-ECU
Ignition System
ignition system. Other procedures are the same
as before.
The engine-ECU controls the two power transistors
(A and B) to turn them alternately ON and OFF.
This causes the primary currents in the ignition
coils (A and B) to be alternately interrupted and
allowed to flow to fire the cylinders in the order
1-3-4-2.
The engine-ECU determines which ignition coil
should be controlled by means of the signals from
the camshaft position sensor which is incorporated
in the camshaft and from the crank angle sensor
which is incorporated in the crankshaft. It also
detects the crankshaft position in order to provide
ignition at the most appropriate timing in response
to the engine operation conditions.
When the engine is cold or operated at high
altitudes, the ignition timing is slightly advanced
to provide optimum performance.
Furthermore, if knocking occurs, the ignition timing
is gradually retarded until knocking ceases.
A
B
Spark plug
3
Cylinder No.
Ignition coil
B A
2 4 1