Bringing this thread back from the dead... thats ok, I'm the OP.
Finally got round to making a smoke tester (soldering iron in jar with babyoil, works brilliantly). Found a pretty obvious leak around the primary turbo intake, mostly from around the worm-clamp head, but also from somewhere on the other side of the fitting. I'm guessing it's time for a new intake pipe... that looks like a b!tch to change.
Cleaned out BBOD solenoids and boost solenoid too, and did hose 10 mod.
Also got a boost guage hooked up a while back... about 10psi on primary, 15psi when secondary comes in. So guessing the bits from turbo's onward are ok.
Saying that, after putting everything back after BBOD cleaning today, I'm only getting 9psi, and nothing later in rev range (5-6k). Almost like there's no secondary now. I think I missed something. Any idea's?