Operating a fuel injector having a hydraulic stop

An engine controller for a vehicle, the engine controller comprising:

• a processor;
• and
• a memory storing a set of instructions, the set of instructions, when loaded and executed by the processor, causing the processor to:
• apply a first current profile to a solenoid drive of a fuel injector to carry out a first injection process, wherein the first current profile includes a first holding current value prespecifying a current level of the current flowing through the solenoid during a holding phase;
• determine a first flux value corresponding to a magnetic flux in the holding phase;
• determine a first force value based on the first flux value, wherein the first force value corresponds to a hydraulic force exerted on the armature by fuel in the holding phase;
• determine a deviation between the first force value and an optimal force value which corresponds to the predetermined fuel pressure;
• determine a second holding current value based on the first holding current value and the determined deviation;
• and
• apply a second current profile to the solenoid drive to carry out a second injection process using the second holding current value to apply a hydraulic force on the armature by the fuel adapted to the optimal force value.

A computer program stored on a non-transitory medium, the computer program, when executed by a processor, causing the processor to:

• apply a first current profile to a solenoid drive of a fuel injector to carry out a first injection process, wherein the first current profile includes a first holding current value prespecifying a current level of the current flowing through the solenoid during a holding phase;
• determine a first flux value corresponding to a magnetic flux in the holding phase;
• determine a first force value based on the first flux value, wherein the first force value corresponds to a hydraulic force exerted on the armature by fuel in the holding phase;
• determine a deviation between the first force value and an optimal force value which corresponds to the predetermined fuel pressure;
• determine a second holding current value based on the first holding current value and the determined deviation;
• and
• apply a second current profile to the solenoid drive to carry out a second injection process using the second holding current value to apply a hydraulic force on the armature by the fuel adapted to the optimal force value.