Method for controlling an injector

A control device for controlling a valve which injects fuel into a combustion chamber of an internal combustion engine, the valve having (i) a valve member which closes a valve opening, (ii) an electric actuator which drives the valve member to carry out strokes for releasing the valve opening, and (iii) a control input for electrical control signals, the control device comprising:

• an engine control unit which is connected to the control input and which generates the control signals as a function of operating data of the internal combustion engine, wherein the engine control unit has a stroke loss model which predicts a reduction of the stroke size as a stroke loss, wherein the engine control unit is configured to continuously incorporate temperature and temperature changes at the valve as well as the number of strokes carried out by the valve member into the stroke loss model, and the engine control unit corrects, by using the predicted stroke loss, the control signals to compensate for the reduction of the stroke size, and wherein parameters of the stroke loss model are empirically ascertained at the valve which is separated from the internal combustion engine.