Big Flat Spot / No Boost Mid Range T5 P2

[V70IIT5]

Well I've driven the V70 P2 T5 twice since the PCV system service, oil change and coolant change, and brake service. On hard acceleration it is as if there is no turbo in the mid range, but if I lift my foot from the accelerator, it seems to pick up better. This car is a recent purchase.

I know there is turbo lag with turbos, and I have been used to driving my Dad's old 850 T5 estate in the past. However, this feels like the turbo is switching itself off and giving no boost.

The vacuum pipes are all in good order, I have checked them. The car is not misfiring, it is running very sweetly. The problem is only under hard acceleration. It kind of runs out of turbo between 2-4 k revs. I can't work it out. Plus the flat spot doesn't seem to be consistently in the same place. I removed the throttle and cleaned it when I did the PCV system.

I can't imagine it could be a clogged fuel filter (which I haven't replaced at 103k miles) or there would be running problems across the rev range....;

Any experienced advice would be appreciated. Thanks.

[V70IIT5]

I wonder if its the turbo valve fitted to the airbox? I replaced one vacuum line from the IM as it was in pieces, but the other pipes looked OK...... I'll replace all the vacuum pipes tomorrow and see if there is any difference....

[V70IIT5]

Well I can't see anything visibly wrong with the vacuum pipes, they are not broken or badly cracked. What does the device with the electrical connector do attached next to the fan with the tube running down to the front of the engine?