Patent ID: 6148611
Filing Date: 2000-11-21
Classification: F02D,Y02T

Abstract:
An air-fuel ratio controller for use with an engine which performs combustion of a mixture of fuel injected from a fuel injector and air aspirated from an intake passage, wherein exhaust gas produced by combustion is purified by a catalytic converter comprising a three-way catalyst, said controller comprising:a sensor for detecting whether or not said engine is running in an idle state,a sensor for detecting a rotation speed of said engine, anda microprocessor programmed to:stop fuel injection from the fuel injector when the engine is in the idle state and the engine rotation speed exceeds a predetermined fuel cut permitted rotation speed,calculate an oxygen amount adsorbed on said three-way catalyst while said injection has stopped,increase the amount of fuel injected from said fuel injector when said fuel injection is resumed, by an increase amount according to said adsorbed oxygen amount, andlimit said increase amount to a predetermined limiting value.