Method for determining fuel composition of e.g. petrol-ethanol mixture for diesel engine of vehicle, involves deriving characteristic for composition of fuel mixture or Lambda value for cylinders from gradients for smooth running of engine

摘要

The method involves negatively and temporarily influencing smooth running of an internal combustion engine by varying an ignition angle and/or by varying an air-fuel-ratio by using an engine control unit. A characteristic for a composition of the actual existing fuel mixture or a Lambda value for cylinders of the internal-combustion engine are derived from the smooth running of the engine and/or gradients for the smooth running of the engine. The adjustment of ignition time and/or the air-fuel ratio is implemented constantly or in stages. An independent claim is also included for a device for determining fuel composition of a mixture of fuels that are utilized for operating an internal combustion engine, comprising an engine control unit.