Does sound like the ICV to me. Do the revs drop if you put the clutch down coming to a stop?
I mean does it drop to the point of cutting out / actually cutting out.
Another test if the ICV is quite bad, is to rev it from standstill to the redline, and if it stalls when the revs drop, it's quite a pointer.
Another test if the ICV is quite bad, is to rev it from standstill to the redline, and if it stalls when the revs drop, it's quite a pointer.