Volvo 960 2.5 170hp Ruckles/Stutters at low speed

Hello all, recently I bought my dream car: Volvo 960 2.5 year 1995. It has only 125,000km of mileage. I noticed a small problem: in the stationary gas it jerks very easily, the speed needle moves up and down minimally. (almost not visible). More serious is that in the 1st course at low speed a real power hole occurs. i.e. I give gas and have the feeling that the engine swallows or it happens completely nothing. But this occurs only at low speed. The car has just received a fresh inspection including the change of all relevant filters. In addition, the workshop has found that the air supply or the plastic/rubber lines which air lead to the engine are porous. These have already been changed, unfortunately the problem has not been solved. There are no control lights on in the car. Autobahnfahrt etc. is all wonderful. What should I research (leave). I am baffled. Sorry my incompetent mail, i I have little idea of cars or the right terms. Thank you for any help. Christian