1988 244 DL, B230F, LH-2.2, 162000 miles

I've been working to resolve a running and idle problem and seem to have gotten the issue down to an idle problem that makes no sense to me.

The car starts fine.
The car drives fine.
The idle recovers after I take my foot of the throttle ...
then the engine gets a mind of its own and starts to increase rpm.
I put a timing light on it and found the engine was at about 18 degrees instead of 12. It's hard to set idle if there is uncontrolled gas being dumped in the engine.

The car can be driven in first gear without using the gas pedal. At stops I need to constantly tap the gas pedal to get the idle to restore the idle temporarily - not to keep it running but to slow it down.

It does this after it is started and warmed up. I was not sure of the problem at first because I had a high idle after adjusting the throttle to begin with.

I adjusted the throttle a second time (stop screw, TPS, link) again with the thought that I was off somewhere and the high idle turned into this racing engine problem.

The best description is that the car operates normally
EXCEPT
that the idle does not stay normal. It recovers to normal after releasing the throttle and then starts to increase rpm as if I was applying gas.