??]I can't see the turbo being faulty. They either work or they don't. If it was damaged and ineffecient you'd get black smoke due to lack of air and you'd notice a loss of torque from under 2000rpm.
If this isn't happening and there are no untoward noises from it, cutting out under full throttle (usually only above 3000rpm) is usually due to a fuel supply problem with this engine. (In tank pump, under bonnet pump, a leaking injector, sticking HP pump control solenoid)
A Tu3 will place extra demands on the fuel system so if you do have a fuel supply issue, the cutting out will be worse with a Tu3 fitted. If it is a turbo problem, then the Tu3 will show up any lack of air as more smoke in the exhaust.
Ron
hp pump solenoid//what where???
underbonnet pump???