Patent ID: 7493887

Claim:
A method for detecting a preinjection in an internal combustion engine with a common-rail system, including individual accumulators, comprising the steps of: detecting an individual accumulator pressure distribution (pE) in a measurement interval and using the individual accumulator pressure distribution to determine an injection end (SE) of a main injection; computing a virtual injection start (SBv) of the main injection by a mathematical function as a function of the injection end (SE); setting the virtual injection start (SBv) as an actual injection start (SB(IST)) of the main injection; determining, with preinjection activated, an actual injection delay (SV(IST)) for the main injection as a function of the actual injection start (SB(IST)); computing an injection delay deviation (dSV) of a set injection delay (SV(SL)) from the actual injection delay (SV(IST)); and using the injection delay deviation (dSV) to determine whether a preinjection (VE) has occurred.