Depending on the Country your vehicle was originally sold in, do you have an owners document telling you the engine code/ specification? My British registration document does. We can also use Ford's ETIS to tell us the vehicle specification (at least how it was when it left the factory), can you do this?
If you have an unused or disconnected vacuum actuator then it sounds very much like somebody has binned the original VNT turbo for a fixed one, especially if they've messed around with the exhaust to make it fit. On the Mk2 TDI's, there are a few other differences between the VNT and fixed turbo variants which may help you confirm what's gone on (assuming that the same differences applied to the Mk1)-the higher powered TDI's (115, 130 and 150ps) had the VNT along with an EGR cooler, a sphere shaped vacuum reservoir on the front of the engine and an anti-shudder flap (butterfly)- with a separate vacuum actuator and it's own vacuum supply- on the EGR valve. I think all of these were lacking on the lower powered variant with the fixed turbo.
Having said all that, what is controlling the turbo wastegate the way it is set up at the moment?
