TDI jiggle from 3000 rpm

Hello, I have the following problem: With my Passat 3C Bj. 2006 2.0 TDI 140 HP 16V the engine jerks off when accelerating from about 3000 rpm. It feels as if the engine does not get enough air. I only typed on the air filter because it was really dirty, but that didn’t bring any improvement. I only test the problem with the warm engine, because I don’t turn a cold one so high. There’s nothing to be noticed about it, even if you let it turn up slowly. What could be the reason? The car has now run almost 100tsd.