IGNITION SYSTEM FOR AN INTERNAL COMBUSTION ENGINE

摘要

An electronic ignition timing control system including means (15, 16) for retarding the ignition timing for all or a predetermined subset of the cylinders (21-24) in a multi-cylinder internal combustion engine (20) during cold starts. Spark timing is reduced for a balanced subset of the cylinders (21-24) for a short time after the engine is started in order to transfer additional heat to the exhaust system to more quickly raise the temperature of the catalyst and thereby reduce undesired emissions.