1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 68Get this manual
3-13 ENGINE CONTROL SYSTEM
ELECTRONIC FUEL INJECTION SYSTEM
The fuel injection system used by the DF4050 is speed-density, multi-point, sequential, electronic fuel injection typeThe fuel injection system is composed of the fuel line components, air intake componentsand components for system control (ECM,sensors, switches, etc
FUEL INJECTION CONTROL SYSTEM
OUTLINE The sensors monitor current engine condition and send signals to the ECMBased on these signals, the ECM determines the optimum fuel injection time duration (fuel amount) and fuel injection timing (multi- point sequential timing) and controls the injector operating signals accordinglyFuel injection start timing is set at BTDC 545 on exhaust stroke constantBasic sensors MAP sensorInforms ECM of intake manifold pressureCKP sensorInforms ECM of engine speed and crankshaft angleCompensating sensors Cylinder temperature sensor: Informs ECM of cylinder temperatureIAT sensor: Informs ECM of intake air temperatureMAP sensor: Informs ECM of barometric pressure at time of engine startingBattery voltage: Signal Others CMP sensor: Informs ECM of camshaft angleCTP switch: Informs ECM of throttle position (openclosed)Neutral switch: Informs ECM of shift position (neutral or not)ECM CPU ECM main relay Sensorswitch signal input (Voltage) Injection time duration