Patent ID: 6276349
Filing Date: 2001-08-21
Classification: F02D

Abstract:
A cylinder-selective control process for an air-fuel ratio of a multi-cylinder internal-combustion engine, wherein a lambda probe arranged in an exhaust pipe system generates a voltage signal corresponding to an air-fuel ratio, said voltage signal being supplied to a computing unit which determines the air-fuel ratio for each individual cylinder, a fuel metering unit being provided to determine a fuel injection quantity at least as a function of a basic fuel injection value and the determined air-fuel ratios of the individual cylinders, and a fuel supply unit being provided for supplying the fuel injection quantity determined by the fuel metering unit to the individual cylinders of the internal-combustion engine, the process comprising the acts of:detecting the voltage signal from the lambda probe in a crank-angle-synchronous manner via the computing unit;assigning the detected voltage signal to a certain cylinder;determining a voltage deviation for each cylinder in relation to the voltage signals assigned to sequentially adjacent cylinders; andcorrecting the fuel injection quantity as a function of the determined voltage deviation.