Thank you John, a very comprehensive answer!
My first thought was the turbo but only guessing at this stage.
Definitely no leaks on the output side of turbo and no restrictions on inlet side apart from the filter of course which is new but it is a 300tdi filter and housing presuming this allows enough flow?
No reason for the pump timing to be out that I am aware of, how do you check?
Starts up fine when cold, little bit slow at turning over sometimes when very cold but does need a new starter motor, some smoke at start up and very occasionally it will run a little lumpy for a few seconds but soon clears.
Looking forward to getting it running right, goes ok as it is so should be good when its going well!

