Problem solved: I'm a bit annoyed with myself as i should have checked this first, I sprayed some water around the inlet mainfold where it bolts onto the head and noticed an amediate change in idle, I removed the inlet manifold and found a split in no4 inlet gasket, Now replaced and all is well ( apart from a leaking steering rack and a lack of finding a good second hand one
)
Hooray, and congratulations!
Thanks for sharing your experience
/Anders