All sorted!
Cleaned up and vaselined the main gearbox earth, replaced two of the temp sensors (left the coolant temp as its fairly accurate), fresh connections on all and used some heat shrink to cover the exposed wires and all is good. Not sure what out of that list actually cured it but it all needed doing so am happy again.
Glad to hear theres nothing wrong with my coil either, got a little stressed trying to find a trailing wire in the bay for!
Cheers to all who helped priceless info as usual.
