Tb45e slight idle issue

[Scottee]

Hi guys , my patrol wagon has developed a slight idle running issue where it idle slightly rough. Have spent a day chasing this problem but cannot find the cause.
Wondering if anyone has had this issue and found the cause.its a tb45e and auto.well maintained 370000km.runs gas and petrol, issue occurs on both fuels. Makes power and it runs great at all throttle ranges.
I've checked valve clearances, changed leads, plugs, checked dizzy, checked tps, checked and tested maf, checked vacuum system, cleaned throttle body and checked and cleaned iac. Checked the in take pipes from air cleaner to throttle body .
Any other things to look for?it has me stumped