SYSTEM / ECM System Fuel Injection Amount Control Purpose: Controls the best fuel injection amount. Operation: 1. ECM detects the engine speed according to the signals from the crank speed sensor and cam angle sensor. 2. MC calculate the target engine speed according to the signals from the engine control dial, sen- sors and switches and sends the signals to ECM. (Refer to SYSTEM / Control System group.) 3. ECM mainly controls fuel injection amount by turning ON/OFF for two-way valve in injector ac- cording to the engine speed and the signals from MC. T2-3-4