Abstract: A fuel injection carburetor in an internal combustion engine, comprising: a fuel injection valve provided at a position upstream of a throttle valve mounted in an intake passage; and an idling bypass air passage bypassing the throttle valve; wherein the range of fuel spray angle of the fuel injection valve is determined such that the fuel injection valve is disposed in such a manner that a position on the surface of the throttle valve, to which the sprayed fuel reaches, is always located at an opening forward end in the downstream direction of the throttle valve rather than an opening forward end in the upstream direction within the total throttle opening of the throttle valve from the full closing to the full opening, there are provided a bypass air valve of a wax-type provided in the idling bypass air passage and in which the higher the temperature rises, the less the flowing area of the bypass air passage is made, and a hot water passage for circulating the engine coolant from a position adjacent the openi

Abstract: A fuel injection apparatus for use in an internal combustion engine, which improves the fuel distribution performance by orienting the fuel injection valve in a position not corresponding to the center line of the throttle bore. The apparatus comprises a throttle body and a control means for directing the fuel injected by the fuel injection valve toward a downstream portion of the throttle valve.

Abstract: A first heat exchanger for heating the wall of an engine intake passage by engine coolant is connected in series with a parallel connection of a second heat exchanger for heating the interior of a passenger compartment and a bypass conduit via a changeover valve which directs flow of coolant alternatively either through the first heat exchanger and the bypass conduit in series and not through the second heat exchanger for summer use, or through the first heat exchanger and the second heat exchanger in series and not through the bypass conduit for winter use. The bypass conduit system has a higher coolant flow resistance than the second heat exchanger, so that the amount of heating applied to the wall of the engine intake passage is automatically reduced when the heating of the passenger compartment is switched off for summer use as compared in winter use where the heating of the passenger compartment is switched on.

Abstract: An air-fuel ratio control apparatus of an internal combustion engine controls the change in the amount of fuel discharged into an intake passage downstream of a throttle valve of the engine more smoothly in accordance with the change in the amount of fuel discharged into the intake passage upstream of the throttle valve. Thus, the air-fuel ratio of the air-fuel mixture fed into the cylinder of the engine is changed smoothly without causing a surging phenomenon to occur in the engine.

Abstract: This application discloses a secondary air control system in an internal combustion engine.