Problems with 1.6 FSI…

Hello, I have been driving an A2 with 1.6l FSI engine (10 Tkm, first registration 11/03) for about 2 months. I love the car – except for some problems with the engine… In idle mode (even running warm), the engine sometimes starts to nail like a diesel! The nailing or “tackering” is clearly felt in the pedals. This behavior is by the way independent of whether the air conditioning is switched on or off (I thought first of the compressor). Second problem: The engine takes at times very fast. This behaviour is particularly unpleasant when starting, because you are either afraid to strangle the engine or start with full throttle. Furthermore, the performance of accelerations is sometimes very unbalanced. In other words: the car gives thrust, then comes a power hole, shortly after that comes thrust again. As I said – only sometimes. Very strange… My workshop thinks that there is no fault stored in the control unit, the nailing is a peculiarity of the FSI-Mo tors and the disappointing torque course (“somewhat weak down” is A2-typical. On my remark that my rental car – a 1.0l VW Lupo! – gets away subjectively better, then came only a shrug… :-)( Can any of you help me? Do I expect too much? Does the workshop have no idea? I really regret my purchase by now… Thanks and greeting, bluenude