Abstract: In controlling fuel injection and ignition timing in an internal combustion engine operating on a fuel mixture, such as gasoline and methanol, consideration must be given to the mixture ratio of the fuel mixture in determining air/fuel ratio and ignition timing, as well as in controlling the atomizing of the injected fuel. Fuel injection time is determined in accordance with air/fuel ratio, which is calculated in accordance with the expressionA/F=14.8-0.0853Pfor a fuel mixture of gasoline and methanol, where P is the mixture ratio of methanol. In addition, to enhance cold start performance, a droplet size of injected fuel below 100.mu. is desired, and this may be achieved using a heating element whose surface temperature is controlled in accordance with the mixture ratio P or by injecting compressed air with the injected fuel in an amount determined by the mixture ratio P, or both.