Abstract: A dual fuel system for motor vehicles having an internal combustion engine with electronic fuel injection equipment designed for use with gasoline fuel, wherein a delivery system for an alternate fuel, such as compressed natural gas or the like, is provided. The alternate fuel delivery system comprises a pilot valve regulated by a separate electronic fuel injector connected to the vehicle's electronic control module is also connected on one side of the pilot valve to a pressurized tank of gaseous fuel, and on the other side to the vehicle's throttle body for delivery of the alternate fuel thereto in the proper amounts called for by the vehicle's original electronic control module. The same electronic control module regulates the amount of alternate fuel such as compressed natural gas delivered to the engine when operating on the alternate fuel as well as the amount of gasoline when operating in that mode.