Abstract: A method for testing a spark-ignited internal combustion engine is proposed, wherein a pulse-shaped signal derived from the ignition system is made available which signal allocates a pulse (34, 34a, 34b) to each switching process occurring in the ignition system. A first pulse (34) of a pulse group (32, 33) of the signal respectively starts a retriggerable timer (16) which, during its active phase (T.sub.A, T'.sub.A), suppresses the pulses (34a, 34b) of the pulse group (32, 33) following the first pulse (34). The time to be predetermined for the retriggerable timer (16) must be predetermined such that it is longer than the maximum interval (T.sub.1, T.sub.2) between the pulses (34, 34a, 34b) of a pulse group (32, 33). The method according to the invention is particularly suitable for testing a spark-ignited internal combustion engine which is provided with an ignition system comprising a spark band ignition.

Abstract: A device is provided for detecting high-voltage characteristics in an ignition system having at least two ignition coils. The device includes a plurality of first capacitive signal couplers each being disposed on a respective one of the ignition coils for capacitively extracting a voltage signal from the ignition coil. A circuit arrangement is connected to the plurality of first capacitive signal couplers and includes an output, and a signal combiner for combining the voltage signals extracted from the ignition coils and producing a combined voltage signal at the output. A plurality of second capacitive signal couplers each connected between the signal combiner and a respective one of the first capacitive signal coupler provides for potential isolation between the plurality of first capacitive signal couplers and a further portion of the circuit arrangement.

Abstract: Methods for associating ignition signals with a reference cylinder in multiple-spark ignition systems of internal combustion engines with externally supplied ignition are proposed; different signal levels for the primary and supporting sparks are used in a first method, and the time offset between the primary and supporting spark onsets is used in a second method for the association.