The problem was the Throttle Position Sensor. Not only had it slipped from it's correct position but the main wiring was a little bit corroded. Lots of cleaning on the connections (and through out the entire loom) and careful positioning of the TPS and it's little plastic connecting piece. Both Power valves had been removed and cleaned and new seals and clips fitted before re-installing. To clean everything up i used very fine wire wool, available from you friendly plumbing supplier. Easy solution to position the power valves is a 5.5mm drill bit (fits a treat).
3 heat cycles done and the power valves move as they should. Of ffor an MOt on Wednesday and we are rolling again after my rebuild

Check out the latest pics

http://www.photobucket.com/user/Mellorp/library/F3NSR?sort=3&page=1

Cheers

Phil M