Patent Document ID: 20140033811
Application ID: 14004155
Patent Flag: 0

Claim One:
1. A method for detecting faulty components of a piezo-injector of a fuel injection system of an internal combustion engine, the piezo-injector having a piezo-electric actuator and configured to drive a nozzle needle operation in a partial-stroke mode and a full-stroke mode, the method comprising: achieving a defined operating point of the internal combustion engine, measuring a first time after which the nozzle needle impacts against a stop during an opening of the nozzle needle, and a second time after which the nozzle needle impacts against a needle seat during a closing of the nozzle needle, comparing the first and second measured times with predetermined time values, calculating one or more parameters of the fuel injection system using multiple different calculation models, and storing the calculated parameters from the multiple calculation models, comparing the calculated parameters from the multiple calculation models with predetermined parameter values, and comparing the calculated parameters from the multiple calculation models with one another.