US Patent 7373918 Diesel engine control system

When a learning condition is satisfied, an operational state of an engine is adjusted in a retarded combustion operation to a misfire inducing state, at which misfire is prone to occur in a cylinder of the engine due to shortage of a pilot flame generative injection quantity. When the misfire is sensed, the pilot flame generative injection quantity of the misfired cylinder is progressively increased. Then, when the misfire is eliminated through this, a pilot flame generative correction quantity at the time of eliminating the misfire is stored. Thereafter, the pilot flame generative injection quantity is corrected based on the stored pilot flame generative correction quantity.