Hi all, thought I'd give a bit of an update. So far here is whats been checked / repaired / replaced.....
air filter
fuel filter
oil filter
oil
sedimenter cleaned
injectors
fuel pump
intercooler
intake manifold
air intake hoses
MAF
boost solenoid
turbo
and guess what, I still have the same issue. I've run out of ideas now
Also, don't know if it makes a difference but mine is the edc 300 tdi so i believe it's not possible to tweak the pump
If you live near me I could give you a hand setting it up !