Finally got the idling issues sorted once and for all. Took off the throttlebody as i had my doubts about maybe taking off too much when sharpening the butterfly. Had a look on the inside of the T/B and noticed there was a gap at the top where the butterfly sits inside the bore. No gap on the bottom and it appeared as though it would not close completely as i could push the lever back and it would move slightly to close completely. So took out the butterfly out and checked that the edge hadnt been grinded/sharpened too much, which it hadnt still had it original little markings around the edge so i put it back in and managed to re position it which was very strange as i thought that it would only go in one way and centre itself when it was screwed in. Got the butterfly to sit dead centre in the bore this time. It now had only the slightest little gaps around the butterfly which could only really be seen when held up in the light. Compared it to the old untouched T/B and it was the exact same both had tiny gaps around the butterfly. Put the modded T/B back in and added a second gasket to in between to make sure there wasnt any air leaks. Removed the isc gasket i made up with smaller holes, chucked the original one back in with normal sized holes. Fired it up, adjusted the idle, took it for a spin and now its sweet. No rev hang and idles about normal now too . Idles at about 650-700 in drive when warm and about 800 in park. Will wait to see how the ecu relearns everything but so far so good