Hi Mark,
I have thought about that but I can't run the actuator test with the engine running (I believe) so have checked the operation of the flap by watching the vac before and after the solenoid valve on a test drive. It has now come to light that he recently disconnected his battery because the radio was playing up so I now think this is a straight forward adaption issue and me cleaning the flap has just exacerbated the situation. With Jon's help (thanks very much Jon) and a bit more searching on Ross Tech I think I have now got the correct channel number (which I will post if successful). By the way, Jon I was sure I had properly checked that the runner was all in one piece but have double checked it to make sure after your email.
I know I should have VCDS for these jobs but as some of you know I should be moving on soon so am loathe to invest for what hopefully will only be a short while.
Once again thanks for all the help and I will keep you updated.
Bryan.