A fuel metering system for an internal combustion engine has an arbitrarily settable throttle plate which controls the air flow through the induction tube and an air flow responsive valve element, shaped somewhat like a cylindrical sector, which is pivoted inside the induction tube upstream of the throttle plate. The pivoting valve element has a shaft which is surrounded by a bushing. An opening in the bushing is uncovered to varying extent by a control edge on the pivotal shaft so as to meter out fuel in proportion to the angular excursion of the pivoting valve element. The fuel is delivered to the induction tube directly downstream of the pivoting valve element.