Abstract: An idle intake control device provided with a backflow preventing means for preventing a backflow near an idle intake regulating valve and producing only a forward flow in order to prevent idle intake air containing combustion products from flowing back and being adhered to an idle intake regulating valve in an idle intake passageway for bypassing an intake regulating valve provided in an intake passageway of the engine.

Abstract: A fuel injection type internal combustion engine provided with a pressure regulator for controlling a constant difference between a pressure of fuel supplied to the injector and a pressure of the intake system at the position where the injector is mounted. A tank is arranged for storing a positive pressure obtained while the engine is operated. A switching valve is arranged for connecting the tank with the pressure regulator when the engine is started when hot. Due to the operation of the regulator for maintaining the constant pressure difference, the pressure of the fuel supplied to the fuel injector is increased, making it difficult for the fuel to vaporize. Thus, preventing a so-called vapor lock.

Abstract: A temperature sensitive negative-pressure control valve is provided with a pressure adjusting means functioning to output a constant negative-pressure which is determined by the biasing force of an adjusting spring, and a temperature sensitive device for varying the biasing force of the adjusting spring, whereby variation of the biasing force of the adjusting spring imparted to the pressure adjusting device according to the temperature detected by the temperature sensitive device warrants outputting of continuously varying negative-pressure in response to the variation of the detected temperature.