CIS stuff for your info.
 

My 1982 engine was always a bit funny about cold weather. It would rev at about 1,800 rpm for ten minutes. It's done this for about ten years I suppose, and I always intended on pulling the AAV apart and cleaning it as this had worked with my 1979 engine.

I was putting a new fuel check valve in the fuel pump to help with a warm start problem that happened occasionally when I noticed some stains on the surrounding are area that looked like a fuel leak had occurred.

So I put a new fuel pump in that was the correct part for the car. The old one wasn't the correct part but had been there for ten years. Now the car doesn't do the 1,800 rpm rev'ing when cold thing and is instead about 1,100 rpm for a minute then runs perfectly when cold.

So this suggests a lot of odd CIS problems are related to the fuel pump and the pressure it puts out and holds.