Thanks for the info, the plan was always to change the temp probe and the ECU anyway I think, so I think this may be the time to upgrade it all!

Have tried to recalibrate everything but as suspected I think it's had it, temp still reading around the 1200 degrees mark and pushing the Ignition button, the engine starts to spin, as soon as the turbine attempts to turn over the GSU read out turns to strange symbols and it stops spinning.

Battery used was the supplied Jetcat 7.2v Nicad, all original cables etc etc

Think it's time for the latest ECU and a new temp probe, thanks for the help guys