jerks at speeding up and loses performance..

Hello everyone, have bought our v40 a 1/2 year ago and swubs after the flow of the guarantee start the problems. have a v40 bj 2001 1.9 with a gdi engine. when I was on the road the last time and accelerated the car began to stutter at approx. 160 kmh and had no more power. when I went off the gas and then slightly accelerated it went again. the next day everything was ok again at the first ride. at the second but the bowl is drunk. after that I could drive again without any problems. in the evening then on the starting again the same. this time already at 120 kmh. what can that be? and can someone recommend me a reliable (volvo) workshop in the room HU/OF/FFM? greet thomas