Abstract: A closed loop, electronically controlled and regulated fuel metering system for operating an internal combustion engine in accordance with a predetermined mass fuel-air ratio scheduled in the controller for different engine operating conditions. Linear air flow and fuel flow measuring devices and transducers responsive to selected ambient fluid and engine operating parameters develop electrical signals, which are related to the air flow rate and fuel flow rate and are modified in accordance with the sensed ambient parameters and a programmed signal from the scheduler representing the fuel-air ratio according to which it is desired to operate the engine over its range of operation.