Control system for internal combustion engines

摘要

A control system for an internal combustion engine controls a fuel injection amount based on operating conditions of the engine and an evaporative fuel concentration-dependent correction coefficient. The control system includes a purge control valve arranged in a purging passage connecting a canister for temporarily storing evaporative fuel generated from a fuel tank and an intake passage. This coefficient is held to a predetermined value for a predetermined time period after purging is permitted, and to another for a predetermined time period after purging is inhibited. In another aspect, the purge control valve is controlled based on operating conditions of the engine and a purging flow rate correction coefficient. This coefficient is held when purging is inhibited, and is progressively set to a larger value depending on the evaporative fuel-dependent correction coefficient, after purging is permitted. In another aspect, when a vehicle on which the engine is installed is started, the purge control valve is controlled based on a special purging control amount which is progressively increased based on a parameter related to a standing start of the vehicle. In another aspect, the operation of the purge control valve is inhibited for a predetermined time period dependent on a temperature of the engine, after the start of the engine. In yet another aspect, the flow rate of purged fuel vapor is corrected in accordance with the amount of exhaust gas recirculation.