S40 2007 petrol. Acceleration problems

[Karl appleton]

Hi
I recently had an MOT and brake discs/ pads all round done on my volvo s40 2.0 petrol (2007) ever since it started on occasion having problems accelerating between 2000-3000rpm basically the acceleration was very sluggish and there was a slight misfire feeling. As soon as it got to 3000rpm acceleration was fine.
Now the cars fine on the first start of the day and if it's below 20c temperature outside but if you stop and then restart or if it's a hot day the acceleration issue is back.
Had it in the garage and they've suggested it needs a new accelerator unit as it's not sending the correct signal? (Apparently it's a wireless system?)
Just wanted to know if anyone else has had this problem or have heard about it before I go ahead and have the work done

Thanks

Karl

[wrinkles]

Sounds like the throttle body needs cleaning to me take it off and use carb cleaner to remove the gunk inside do not remove the sensors just un plug them. or failing that it could be the air sensor or Mas.