System for controlling engine

摘要

An engine control system causes a NOx trapping substance to release absorbed NOx by increasing an amount of fuel and spraying the fuel through primary fuel injection which is made at a primary fuel injection timing near a dead top center of a compression stroke and post-fuel injection which is made at a post-fuel injection timing between an expansion stroke and an exhaust stoke after said primary fuel injection with a retardation which is large at the beginning of implementation of the post-fuel injection and, thereafter changed small.