Patent ID: 7962277

Claim:
A method for operating an internal combustion engine, which comprises as least two cylinders, an induction tract and an exhaust-gas tract, which communicate with a combustion chamber of one of the cylinders depending on a switched position of at least one of a gas inlet valve and a gas exhaust valve, and which, for each of the cylinders, comprises at least one injection valve and a piston, with said piston being connected to a crankshaft of the internal combustion engine, the method comprising the steps of: determining whether one or more necessary diagnostic conditions for a diagnosis of uneven running of the internal combustion engine are currently present, if at least one of the necessary diagnostic conditions are currently present, determining whether the internal combustion engine is functioning fault-free with respect to uneven running by: determining a cylinder-specific engine weed of each of the cylinders relative to a position of the crankshaft, determining whether the cylinder-specific engine speed of each cylinder lies within a corresponding predetermined speed range, and determining that the internal combustion engine is functioning fault-free with respect to uneven running if it is determined that all cylinder-specific engine speeds lie within the corresponding predetermined speed range, if it is determined that the internal combustion engine is functioning fault-free with respect to uneven running: determining a current value of a cylinder-specific injection quantity for each cylinder depending on a control input to the relevant injection valve, assigning the current value of the cylinder-specific injection quantity to a reference value of the cylinder-specific injection quantity at a current operating point of the internal combustion engine, and storing the reference value of the cylinder-specific injection quantity.