Had a problem with my car and below is a description, don't know if its the same as yours but good luck.
Car starts fine but some times as soon as I move off I can feel something’s not quite right, car is very sluggish and the throttle has to be pushed down considerably further than usual to get it to pick up ? Once I’m moving the car drives fine if a bit unresponsive, then without warning and with no further movement of the throttle the car will start to pick up and gain speed up to a certain point. From now on the car will drive and accelerate as it should but only up to about 3200 – 3500 rpm, from this point on it feels as though the car is wading through custard and it creeps (and I mean creeps !) toward the red line. Once another gear is selected the same thing happens and it again only revs freely to the above figures.
It turned out to be the turbo actuator control solenoid !