I have posted a couple of times regarding this issue. It drives ok when i start up for a few minutes, the longer its left the longer it seems to drive okay after start up. I bought the car for 600 and I've spent 300. The turbo works great when its running fine but then it goes in to limp mode after a short time. What i have done so far:

1. Changed MAF sensor
2. Changed MAP sensor
3. Checked Vacum pipes (ALL OK)
4. Change air filter, oil filter and fuel filter

I then took it to a BMW specialist, he plugged it in and it came up with boost pressure sensor.

1. Changed boost pressure sensor
2. He has checked the wiring from the boost pressure sensor (ALL OK)
3. Ran a solder iron over the ECU computer board connections

After this he says it was okay for a while but then back in to limp mode.

He advised it could be the ECU at fault but they are not common but they do go wrong as his computer is still showing the connection from the boost pressure sensor to the ECU as being the fault.

He didn't seem convinced though and neither am i, so before putting more money in to it i was wondering if anyone can offer any advice on possible solutions to this problem without having to pour more money in to it.

I am assuming the air mass meter has been programmed as well due to the fact that its not been a constant fault, after cleaning the sensors originally it worked fine for a good half hour or so which wouldn't suggest it needs programmed and the MAF i changed is the same part number as the one that was on.