Power loss/won´t accelerate X3

[Huzz]

Hi, I own an BMW X3 2.0d 2006 manuel 6 gear,with 150.000km on the meter. My car was still for 3 months and after I started to use my car I noticed that I couldnt accelerate from 50 km/h to 70 km/h. The car started to hack and I had power loss but after a spinn at the highway for a couple of km with a lower gear and higher rpm the car started to work as usuall. But now I noticed that I cant drive faster than 150 km/h, it´s just wont accelerate. But between 0 - 150 km/h the car works as usual, no hacking no power loss.

I have followed the service program, and I changed all the filters last year inclusive the fuelfilter. Yesterday I disconnected the battery but that didnt solve the problem either.

Does anyone have an idea what this could be, should I change the fuelfilter or could it be a problem with the MAF.

Thanks in advance
Regards Huzz