Conversion system with electronic controller for utilization of gaseous fuels in spark ignition engines

摘要

A conversion system for converting a spark ignition engine to operate on gaseous fuel is disclosed. The conversion system includes an electronic controller which operates on several novel principles to provide superior performance/responsiveness and to reduce exhaust emissions. The controller in accordance with the invention assumes complete control of spark ignition timing when gaseous fuel mode is enabled and generates independent spark ignition signals tailored to the gaseous fuel. The controller also generates an independent pulse width modulated gaseous fuel injection signal that controls a high performance electronic solenoid injector valve to supply gaseous fuel to the engine. Variable injector speed is used to compensate for the dynamic range of the engine. A novel dual array block learn scheme is used to provide efficient fuel control in engines equipped with closed-loop monitoring systems and exhaust gas recirculation. A gasoline power boost mode is also provided to enable extra power when maximum engine torque is commanded. The advantage is an efficient fuelling system which provides all of the advantages of gaseous fuels while preserving the power capabilities of liquid fuels, and minimizing exhaust emissions.