Fuel control system

A fuel control system for an internal combustion engine fueled by a gaseous and a liquid fuel, comprising

• gaseous fuel flow rate control means including flow rate determination means responsive to engine load variables including a signal generated by a transducer indicating such variables,
• said control means including valve means actuable to vary the gaseous fuel flow rate, said valve means being actuated responsive to the signal generated by the gaseous fuel flow rate determination means,
• liquid fuel control rate determination means including injection pump control means controlling the flow rate of liquid fuel pumped into the engine,
• a transducer responsive to pressure difference across said valve means generating a signal indicating the pressure difference,
• said flow rate determination means including information storage means relating the pressure difference across said valve means, the desired gaseous fuel flow rate and the magnitude of the signal required by the valve means to provide the desired gaseous fuel flow rate,
• a control algorithm in connection with said gaseous flow rate determination means and liquid fuel flow rate determination means determining the desired liquid and gaseous fuel flow rate,
• a second information storage means containing information relating to engine speed, desired fuel flow rate and the magnitude of the signal required by the injection pump to produce the required liquid fuel flow rate,
• said control algorithm responsive to any given engine speed derives from said second storage means the signal indicative of the liquid fuel flow rate which it feeds to said injection pump actuation means,
• a third storage means containing information relating position of a liquid fuel governor and a desired gaseous fuel flow rate,
• said control algorithm determining the desired gaseous fuel flow rate given the position of the liquid fuel governor using the third storage means which is influenced by at least one engine variable of speed and
• including switch means for use of liquid fuel only and in the alternate permitting use of liquid and gas fuel.