ENGINE CONTROL SYSTEM 3-15
CONTROL MODE
BEFORE START :
When the ignition switch is turned “ON”, the ECM receives a MAP sensor signal, indicating the static baro-
metric pressure of the intake manifold. This signal is used to compensate the fuel injection map for altitude.
WHEN CRANKING :
Fuel is simultaneously injected to all cylinders every time any piston is positioned at compression stroke.
AFTER START (FAST-IDLE FUNCTION):
The fuel injection amount is controlled to remain increased until the timer, set according to cylinder tempera-
ture at the time of engine start, expires.
WHEN IDLING / TROLLING :
The fuel injection amount is controlled to maintain a stable engine speed at the specified idle / trolling rpm.
WHEN ACCELERATING :
The fuel injection amount is controlled to increase.
WHEN DECELERATING :
The fuel injection amount is controlled to decrease.
The fuel injection is also cut off on very rapid engine deceleration.
FUEL INJECTION TIMING CHART
In. Cm. Ep. Ex. In. Cm. Ep. Ex. In.
TDC TDC TDC TDC
10˚
120˚ 120˚ 120˚
4-signals/720˚
34-signals/360˚
Injection time duration
BTDC 445˚ on exhaust stroke
CKP sensor
signal
CMP sensor
signal
#1 Injection
signal
#3 Injection
signal
#4 Injection
signal
In. : Intake, Cm. : Compression, Ep. : Explosion, Ex. : Exhaust, TDC : Top Dead Center
ON
OFF
TDC TDC TDC TDC
TDC TDC TDC TDC
Ep. Ex. In. Cm. Ep. Ex. In. Cm. Ep.
TDC TDC TDC TDC
Cm. Ep. Ex. In. Cm. Ep. Ex. In. Cm.
#2 Injection
signal
Ex. In. Cm. Ep. Ex. In. Cm. Ep. Ex.
30˚
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