Suzuki DF140WT User Manual

3-14 ENGINE CONTROL SYSTEM
ELECTRONIC FUEL INJECTION SYSTEM
The fuel injection system used by the DF90/DF115 is a speed-density, multi-point, sequential, electronic fuel
injection type.
The fuel injection system is composed of the fuel line components, air intake components, and components
for system control (ECM, sensors, switches, etc.).
FUEL INJECTION CONTROL SYSTEM
OUTLINE
Sensors are mounted at precise locations on the motor to monitor the current conditions of engine operation
and send signals to the ECM. Based on these signals, the ECM determines the optimum fuel injection time
duration (fuel amount), fuel injection timing (multi-point sequential timing) and controls the injector operating
signals accordingly.
Fuel injection start timing is set at BTDC445° on exhaust stroke constant.
ECM
CPU
Sensor / switch
signal input
Injector
Ignition
switch
Battery
60A fuse
Rectifier &
regulator
Battery
charge
coil
ECM
main
relay
30A fuse
(Voltage)
Injection time
duration
12V
A terminal voltage
(Time)
Basic sensors
Compensating sensors
Injector
MAP sensor :
Informs ECM of intake manifold pressure.
CKP sensor :
Informs ECM of engine speed and crankshaft angle.
Cylinder temperature sensor :
Informs ECM of cylinder temperature.
Fuel injection time duration
(amount) is determined by
a digital map designed in
relation to intake manifold
pressure and engine speed.
Fuel amount compensation
Others
CMP sensor :
Informs ECM of camshaft angle.
CTP switch :
Informs ECM of throttle position (open / closed).
IAT sensor :
Informs ECM of intake air temperature.
MAP sensor :
Informs ECM of barometric pressure at time of engine starting.
Battery voltage :
Constantly monitored by the ECM.
Multi-point sequential timing
Signal Signal Signal
Neutral switch :
Informs ECM of shift position (Neutral or in gear).
Signal
ECM

Suzuki DF140WT Specifications

General

Brand	Suzuki
Model	DF140WT
Category	Outboard Motor
Language	English