Stocking at 2000 RPM

Hi, yesterday on the road short twitch. that in a rafic II dci 1.9 Bj 2003 After that in urban traffic repeatedly twitch when UPM over 2000… After that I gave dme all the attention. So whenever I went over 2000 came a jerk and the engine stopped and then fell back under 2000 as soon as this was exceeded again that same. I could only drive if I switched early, he did pull in this UPM area normal. Sometimes the engine/glow candle light went about 5 km. After that a short turn off, looked if something is loose somewhere, was also at night thanks to time change. Nothing seen. Continued to make the 5 km home. In short, nothing at all he regulated from about 1600 RPM, 3 km were still to be mastered, shortly in the city stopped waiting for 5 minutes again I could drive the remaining 3 km normally without the jerking. Since then, I have not driven any more. What could be the cause? ICh must confess that I used to use the car every day because of work (30-40tkm) until February since then only very sporadically should be called once a week about 20 km otherwise the only place is around… Shame on my head. The trip that had preceded the whole yesterday was a total of 250km on a sunny Sunday noon!