Righto, further on from the idling problem which has now been fixed ( a dirty and clogged Idle Control Valve), my AVC-R now doesn't want to control the boost.
Its set up to limit boost to 0.75 bar, with 71% solenoid duty.
However, at about 0.3-0.4 bar, the solenoid is clicking like crazy and as soon as I get to 0.75 bar, it carries on going and stops at the boost limit on the PowerFC (1 bar).
I've checked all connections and they're fine (and correct), and presumably as the solenoid is clicking, then that too must be connected.
Could it be possible that the solenoid is broken? I'm going to test it tomorrow with one borrowed off a friend, but if it is, where would I get a replacement Apexi solenoid from?

 

Further to above, someone suggested that the wastegate could be jammed. Presumably as I can hear it chattering its not jammed shut? There are no kinks in the lines. I've not managed to test it yet, but are these the symptoms of a dead solenoid?

 

I've replaced the solenoid and it's still doing it. If I increase the boost on the AVC-R, it appears to be able to control it and vents it via the wastegate, but its having a real problem with 0.75 bar?

 

Turn your solenoid duty down to about 50%.

 

Poss - That seems to have worked, thanks

Someone suggested that I could have had the problem as I was originally taking the air feed from somewhere after the throttle body and as i'd moved it to the intercooler piping just after the turbo, this could be causing the problem.