I have not one but two def td5s and both have the same problem that no one else seems to have ! pulling up through the gears and it loses power for a few seconds and the kicks out smoke and then seems ok for a few more seconds and it keeps doing it more so in 3rd 4th and 5th gears ! now its had a new turbo, EGR valve and the wiring in the top of the head also no oil in the ecu or in the red plug,
any ideas would be helpful!

Get the same issue once a year ! MAF sensor, replace with original equipment and should sort problem out.

MAF sensors are prone to go and give the symptoms you describe.