Fuel supply system

A fuel supply system for a mixture-compressing internal combustion plural cylinder engine having internally-supplied ignition, and including a primary mixture formation unit disposed in a common intake tube having branches leading to individual cylinders of said engine and at least one supplementary mixture formation unit also disposed in each of the branches thereof, characterized in that at least one ultrasonic atomizer nozzle serves as said supplementary mixture formation unit and is disposed in said intake tube branch downstream of said primary mixture formation unit, triggering of each of said ultrasonic atomizer nozzles is effected by programmable means stored in a memory of an electronic control device, said memory having stored therein a performance graph showing the non-uniform distribution of the mixture to the individual cylinders of said engine, and said engine further including individual exhaust manifold lines, and exhaust sensor means in each of said lines for detecting oxygen content in the exhaust gas, and for controlling said at least one ultrasonic atomizer nozzle via said electronic control device.