Ignition monitoring system for internal combustion engine

摘要

The internal combustion engine has a monitoring system to detect misfiring in individual cylinders by measuring the ionic current during the burn. To eliminate errors due to the spark induced ionic current, the monitoring window is offset from the start of the firing pulse by an amount greater than the firing pulse length. The start of the window is offset by at least 5 degrees from the end of the firing pulse and the length of the window is related to the engine speed, e.g. 100 degrees for low speeds to 60 degrees for high speeds. The integral of the ionic current in the window is compared with a standard value and any results below that value indicate the misfiring.