Method and device for detecting the idle stroke of injectors

A device for detecting the idle stroke of injectors of an internal combustion engine having a common rail system, comprising

• a fuel pressure accumulator,
• an injector connected to the fuel pressure accumulator,
• a rail pressure sensor, and
• a control unit for actuators of the injectors, wherein the control unit is operable to change an actuator energy until the rail pressure sensor detects a discontinuity in the course of the rail pressure over time, and wherein the device has a memory unit and the control unit is further operable after detecting the discontinuity to store the set actuator energy and the current rail pressure as a measure for the idle stroke of the injector.

A device for detecting the idle stroke of injectors, in particular piezo injectors, of an internal combustion engine having a common rail system, comprising:

• means for setting a constant rail pressure, a continuous rail pressure drop, or buildup,
• means for measuring the current rail pressure,
• means for activating at least one injector actuator by an amount of actuator energy,
• means for changing the actuator energy,
• wherein the means for setting, measuring, activating, and changing are operable until a discontinuity occurs in the course of the rail pressure over time, and
• means for storing the set actuator energy and the current rail pressure after detection of the discontinuity as a measure or the idle stroke of the injector.