AIR-TO-FUEL RATIO CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINE

摘要

An electric-type air-to-fuel ratio control system for an internal combustion engine in which the air-to-fuel ratio sucked into the cylinders of the engine is maintained substantially constant following abrupt deceleration. In accordance with the invention, a bypass flow of air is provided into the intake manifold of the engine downstream of the throttle valve and a fuel injection valve using an electrically controlled air supplying device. The air supplying device is opened following closure of the throttle valve to supply an additional flow of air which compensates for overrichness in the air-to-fuel mixture caused by the delay of fuel injected from the fuel injection valve to the cylinders of the engine. Preferably, the time during which air is supplied through the air supplying device and the flow rate of air therethrough is adjusted so as to maintain a predetermined air-to-fuel ratio following deceleration.