WRXGC82000,
I think my problem relates to the IACV. Spikey was kind enough to loan me one that is known to be good and the problem seems to have cleared. Only very occasionally it hunts a little but no where near what it used to be. Have ordered an aftermarket IACV from the US and hopefully it will arrive either end of this week or next week.
Will let you know how it goes. I didn't know how hard that little IACV works to maintain the idle and I think after a while it must react too slowly.
Am keeping my fingers crossed otherwise it will be back to the drawing board