"Art, that sensor in the bell housing isn't ringing any bells..."

It isn't in the bell housing, it is in the block casting. Perhaps that's why no bells are ringing.

Here's an old pic marked up to show where it is, even if the shape of it isn't that clear.



"1984 was the end of the K-Jet years, so that kind of suprises me we're talking about an '89 780 LH 2.2 here that has one."

This sensor provides the crank timing for spark. Fuel, whether carbs, k-jet, or LH has nothing to do with it. I'd guess the only place you'd have found a "Monotester" to connect to it in those days would have been a Volvo dealership service department. It would have helped with the ignition timing and dwell settings you and I use a timing light and tach/dwell meter to perform.

Here's another memory jogger.



The connector has a dummy plug in it to keep it clean. Cars that have survived to this era may have lost this decor.

--
Art Benstein near Baltimore

In 1980, the Winchester drive was born; based on a model from 1973. IBM introduced the 3340 "Winchester" disk system, the first to use a sealed head/disk assembly (HDA). Almost all modern disk drives now use this technology, and the term "Winchester" became a common description for all hard disks, though generally falling out of use. Project head designer/ lead designer Kenneth Haughton named it after the Winchester 30-30 rifle (initially called the "30-30" because of its two 30 MB spindles).