METHOD AND APPARATUS FOR CLEAN COLD STARTING OF INTERNAL COMBUSTION ENGINES
An improved starting system for internal combustion engines that normally use a liquid fuel such as gasoline. Gaseous fuels such as hydrogen, natural gas, propane, butane, and the like are used in place of the liquid fuel during engine (10) starting and for a selected period thereafter. When starting is initiated, the gasoline introduction system (33, 34, 38) is disabled and introduction of gaseous fuel is initiated. Rapid engine start promptly occurs, even under very cold ambient conditions. Once the engine (10) has started and has run for a period sufficient to reach a reasonable operating temperature, the gaseous fuel introduction system is interrupted and the gasoline system is enabled and provides the fuel thereafter. If desired gaseous fuel flow may continue for a short period after liquid fuel flow has begun.