Abstract: An engine air and fuel controller for a vehicle internal combustion engine is described wherein the mass fuel flow rate is controlled directly in response to vehicle operater command. The engine throttle is positioned by an electronic controller in response to the fuel flow rate to achieve a mass air flow rate determined to produce a scheduled air/fuel ratio. The controller includes a circuit which is responsive to the engine speed to limit the minimum value of the commanded fuel flow rate in accord with a predetermined schedule at a rate whereat the engine throttle is controlled to a scheduled open position during engine overrun conditions to improve engine operation.