Misfire detection in multicylinder engines involves comparing rough running values for simultaneously ignited cylinders with value lower than for individually ignited cylinders

摘要

The invention relates to a method for engine misfire detection in multi-cylinder internal combustion engines with multi-cylinder spark ignition. According to the inventive method, rough running values are detected during every crankshaft rotation by measuring the segment times. Said segment times comprise the piston movement of individual cylinders according to intervals that correspond to their ignition intervals in which the crankshaft covers a pertaining angle of the circular segment. The inventive method allows detection of a misfire in the corresponding circular segment zones of the crankshaft on the basis of the detected rough running values (LUT) by comparing a desired value with a threshold value (SW2). If a misfire in a crankshaft segment zone with multi-cylinder spark ignition is detected, a misfire operation is produced in one of these cylinders. Once the misfire operation is carried out by the engine intervention, the cylinder is detected which has a misfire without engine intervention by measuring the change in the rough running values in the crankshaft segment zone with multi-cylinder spark ignition.