1. An electronic control fuel injection system for a spark ignition internal combustion engine having a throttle valve for preferentially determining fuel flow rate and subordinately determining air flow rate to the engine in response to the fuel flow rate and the engine operating state comprising: an accelerator pedal having a stroke from an idle position to a maximum position; fuel command means driven by said pedal for producing a fuel command signal varying in accordance with a non-linear mathematical function of the distance of said pedal from its idle position and derivatives or differences of said distance with respect to time; reshaping means for selecting a particular said non-linear function; fuel metering means for discharging the fuel in accordance with the command from said fuel command means; at least one fuel injector for injecting said fuel discharge amount into said engine; intake air flow sensing means for detecting the amount of intake air to said engine; computing means for selectively receiving output signals from said fuel metering means indicating said fuel discharge amount and output signals from said intake air flow sensing means indicating actual air flow, and calculating an optimum air supply amount, and throttle valve servo means for determining the openng of said throttle valve according to the output from said computing means to provide said optimum air supply amount to said engine.