Method for analyzing the efficiency of the high-pressure pump of a fuel injection system

1. A method for analyzing the efficiency of the high-pressure pump of a fuel injection system, comprising:

analyzing an efficiency of the high-pressure pump related to individual pump strokes of the high-pressure pump,

wherein the analysis includes:

detecting and analyzing a pressure build-up or a pressure dissipation for each individual pump stroke, and

determining a state of individual components of the high-pressure pump based on the analysis of the pressure build-up or the pressure dissipation for each individual pump stroke.

2. The method of claim 1 , comprising:

analyzing the pressure build-up during a pump stroke to determine an instantaneously prevailing duty point, and

determining a functional capability of an inlet valve of the high-pressure pump based on the analysis of the pressure build-up.

3. The method of claim 2 , comprising:

defining a reference profile for the pressure build-up for a multiplicity of duty points,

comparing the reference profile with a pressure build-up profile determined from measured pressure values,

identifying the inlet valve as being faulty in response to a determination of deviation of the determined pressure build-up profile from the reference profile greater than a threshold value, and

identifying the inlet valve as being free of faults in response to a determination of a deviation of the determined pressure build-up profile from the reference profile less than the threshold value.

4. The method of claim 1 , comprising:

analyzing the pressure build-up during a pump stroke for a plurality of duty points with a different pump stroke frequency, and

determining a presence of a leak between a plunger of a cylinder of the high-pressure pump and an associated cylinder liner based on said analysis.

5. The method of claim 1 , comprising:

analyzing the pressure dissipation after a pump stroke, and

determining a functional capability of an outlet valve of the high-pressure pump based on the analysis of the pressure dissipation.

6. The method of claim 5 , comprising:

defining a reference profile for the pressure dissipation,

comparing the reference profile with a pressure dissipation profile determined from measured pressure values,

identifying the outlet valve as being faulty in response to a determination of a deviation of the determined pressure dissipation profile from the reference profile greater than a threshold value, and

identifying the outlet valve as being free of faults in response to a determination of a deviation of the determined pressure dissipation profile from the reference profile less than the threshold value.

7. The method of claim 1 , comprising:

analyzing each cylinder of the high-pressure pump individually, and

determining a functional capability of components of each respective cylinder based on the analysis.

8. The method of claim 7 , comprising determining a functional capability of the high-pressure pump in its entirety based on the analysis of each cylinder of the high-pressure pump.

9. The method of claim 1 , comprising performing the method during the normal driving operation of a motor vehicle.

10. The method of claim 9 , comprising storing data determined during the normal driving operation and relate to the functional capability of the components of the high-pressure pump in a memory in a non-volatile manner.

11. The method of claim 9 , comprising:

identifying advanced wear of one or more components of the high-pressure pump based on data relating to the functional capability of the components of the high-pressure pump during the driving operation, and

lowering a maximum permissible pressure in the fuel injection system in response to identifying advanced wear.

12. The method according to claim 1 , further comprising detecting and analyzing both a pressure build-up and a pressure dissipation for each individual pump stroke, and

determining a state of individual components of the high-pressure pump based on the analysis of the pressure build-up and the pressure dissipation for each individual pump stroke.