Great day today, went to see the ever helpful Phil200tdi for some tinkering. Never managed to track down exactly what the issue was but, with Phil's help narrowed it down massively.
Today we changed all the vac lines except the 2 turbo ones [ pain in the rear to do as engine was to hot] even though, Phil still tried it but the front was just to tight to pull off.
Removed both vanos solenoids and cleaned them then swapped them over and went for various runs. Got some strange results when testing the vac system. Instead of idling at about 10inhg, my car would idle at 0
On a run the vac was hitting 18inhg [which it should on the G4 board ] but, once there gradually lose vac and throw a 30FF. Thanks to Phil's help it looks like I can now rule out the boost side being the issue
So the next thing to do is get the 2 turbo lines done and install my 2nd boost solenoid.
To cap off a good day, Phil took me out in his car.
Holy S%^& that thing is a monster. I drove home thinking "Must have meth, must have meth!"
Thanks for all the help today mate, top bloke.