Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 634

<MPI>
Interruption of the primary current flowing in the
primary side of the ignition coil generates high
voltage in the secondary side of the ignition coil.
The high voltage thus generated is directed by the
distributor to the applicable spark plug. The engine
firing order is 1–3–4–2 cylinders.
On application of high voltage, the spark plug
generates a spark to ignite the compressed air fuel
mixture in the combustion chamber.
The engine-ECU makes and breaks the primary
current of the ignition coil to regulate the ignition
SYSTEM DIAGRAM
Vacuum sensor
Engine coolant temperature
sensor
Throttle position sensor
Vehicle speed sensor
Ignition switch–ST
Detonation sensor
ENGINE ELECTRICAL –
Crank angle
sensor
Engine-ECU
Power
transistor
To tachometer
Ignition timing adjustment
terminal
Ignition System
timing.
The engine-ECU detects the crankshaft position
by the crank angle sensor incorporated in the
distributor to provide ignition at the most appropriate
timing for the engine operating condition.
When the engine is cold or operated at a high
altitude, the ignition timing is slightly advanced to
provide optimum performance to the operating
condition.
Furthermore, if knocking occurs, the ignition timing
is gradually retarded until knocking ceases.
Distributor
Ignition coil
16-35
Ignition
switch
Battery
Spark
plug