Abstract: A method and apparatus for the limitation of the action of a manual choke by the recirculation of exhaust gases to the intake manifold is disclosed. A vacuum valve is located in a conduit connecting the intake and exhaust manifolds. The vacuum valve is activated by a vacuum transmitted through a conduit connected with the carburetor. The conduit is selectively opened by an electrovalve. The electrovalve receives a signal to open the conduit when the manual choke is activated and an engine temperature sensor indicates that the engine temperature has exceeded a predetermined value. A time delay circuit may delay the sending of the signal to the electrovalve.

Abstract: An arrangement for controlling the recirculation of exhaust gases within internal combustion engines, includes a recycling system of conduits connecting the engine exhaust manifold to the main inlet manifold of the carburetion system and having a recirculating valve interposed within such circuit. The obturator of the recirculation valve has a truncated-cone configuration of such design that the increase in the variable area of the opening between the stopper or obturator and its seat is a function of the engine speed and load. In recycling the exhaust gases, the invention serves as an antipollution means for the exhaust gases of internal combustion engines.