http://forums.pelicanparts.com/uploa...1586368374.JPG
http://forums.pelicanparts.com/uploa...1586368374.JPG
http://forums.pelicanparts.com/uploa...1586368374.JPG
http://forums.pelicanparts.com/uploa...1586368374.JPG
http://forums.pelicanparts.com/uploa...1586368374.JPG
http://forums.pelicanparts.com/uploa...1586368374.JPG

I meant the Code here which is needed, .... but your pics show a WR5 heat rate and thats perfect for your '82 930/16 engine SC.

Awesome, thankyou

Pics 1-3 are all lean. 4&5 are good. 6 is lean.

Reiver's advice is good for a carb'd car but yours has CIS injection. Your plugs should all look like 4&5 in the second set of pics. I'm not familiar with how the SC meters air but I'd say you have a massive amount of unmetered air getting in the system or injectors that are plugged. You might check your intake gaskets and verify your entire vacuum system. Also might have to look at your base idle mixture although I'd think if it was a base idle mixture issue it would show across all cylinders.

In case of CIS a lean plug reading could result from
- a too low initial CO setting (in case of non lambda based CIS)
- wrong air sonsor plate setting (yezz a usually unknown risky reason)
- non proper enrichment regulated by the vacuum of the WUR (at non lambda based CIS) when driving at higher rpms
- false air at common CIS parts (as you mentioned)

But as the outer ring of the plug is dark/sooted enough I would say the air fuel ratio here is ok.
If the center electrode and especially the ground electrode are too bright or even come with a clear visible sort of granules the combustion of this cylinder results simply too hot.
But here with Kerschbaumers pics I would not be concerned.

This is all great stuff, thankyou for helping me learn about this.

The cruelty of this Covid thing is I have tonnes of time to work on the car, but my healing collar bone does not allow for it. Broke it in Nov - had surgery w metal plate, early Jan I re-broke it while cracking a nut to remove AC - actually snapped the metal plate. Every time I pick up a wrench now it aches and tells me to stop.

Enough with the self pity, moving froward very slowly, was thinking maybe send out the injectors to get cleaned just because, and once I can get the tune up finished - see how she runs and check for vacuum leaks and go from there.