Long shot, but here goes:

There is what appears to be a vaccume pipe (grey) coming off the top of my throttle body, it dissappears down behind my coil pack where it connects to what looks like a solenoid, this is bolted onto the manifold directly under the coil pack. The only way to view this mystery 'thingy' is to remove the dump valve from the intercooler. My local 'scooby parts man' (SGT) identified it as a wastegate solenoid.............it isn't. Does anyone want to hazzard a guess?
Car is an MY00 (Classic) Turbo.

 

Fuel vapour purge solenoid, it periodically allows engine vacuum to pull fuel vapour out the tank, through the charcoal filter and into the engine.

 

Once again, the all seeing, all knowing oracle that is Scoobynet and it's followers comes through !!!

Thanks so much for your reply......although I have to admit, it sounds exspensive !!!!