A fail-safe method and system against sticking of the throttle valve (3) are disclosed for automotive engines of a type with a fuel supply unit (2) and a throttle valve (3) driven through an actuator (4). The amount of depression of the accelerator pedal (11) is detected by an accelerator pedal sensor (9). The system further comprises a device (203) for detecting that the throttle valve (3) is sticked, and a device for controlling the fuel flow rate from the the fuel supply unit (2) in accordance with the output of the accelerator pedal sensor (9) when the throttle valve is sticked. The system preferably further comprises an auxiliary air path bypassing the throttle valve (3). The bypass air amount from the auxiliary air path is controlled if the throttle valve (3) is sticked at a low opening degree, while the fuel flow rate of the fuel supply unit (2) is controlled if the throttle valve (3) is sticked at a middle or high opening degree.