ENGINE SPEED CONTROLLER FOR INTERNAL-COMBUSTION ENGINE

摘要

PURPOSE:To control engine speed stably by reducing suction air flow at least for the delay time until fuel supply will increase upon dropping of engine speed during idling thereby preventing increase of air/fuel ratio. CONSTITUTION:A controller 520 comprising a microcomputor will decide whether it is normal idling or warm-up operation from water-temperature through a sensor 511 and engine speed through crank angle sensor 620 to determine fuel injection and bypath throttle valve 516 opening in accordance with the difference between each target speed and actual speed. Upon dropping of engine revolution, suction air flow is reduced at least for the delay time untill fuel supply increase to prevent increase of air/fuel ratio. In such a manner, variation of air/fuel ratio during idling can be prevented to control engine speed stably under idling.