Abstract: The invention is directed to a method of detecting combustion misfires of an internal combustion engine wherein an ion current is generated during the operation of the engine. The ion current signal is detected over a pregiven time interval starting with the discharge of a spark plug. The ion current signal is integrated over time with a weighting function to obtain a weighted integrated signal and the weighting function is adapted to previously detected ion current signals. The maximum of the weighted integrated signal is compared to a threshold value (s.sub.-- io) dependent upon engine rpm (nmot) and load (rl). A fault signal is outputted when the threshold value (s.sub.-- io) is not exceeded. The invention is also directed to an arrangement for detecting the combustion misfires.

Abstract: The invention is directed to a method for controlling the idle of an internal combustion engine having an intake channel for conducting air to the engine. The method utilizes sensors for generating signals characterizing the operating state of the engine and for supplying the signals to a control apparatus. A tank-venting valve is provided through which air can be conducted into the intake channel when the tank-venting valve is open. Control quantities are computed in the control apparatus in dependence upon the signals for at least the following: the tank-venting valve, an idle adjuster device, a fuel metering device and an ignition device. The air supplied to the engine is controlled with the aid of the tank-venting valve. The invention is also directed to an arrangement for carrying out the method.