I typed a huge thread and lost it! Grrr
Look at this thread for adjusting fuel pressure. Do the pressure test again and see if you are losing pressure when you shut it off. Shaef had a bad injector and rebuilt his throttlebody because of it:
You must have a thermostat that reaches operating temp of at least 185. You can check it by measuring the coolant temperature in the radiator. It will be about 10 degrees lower then the engine coolant so use a meat thermometer and check for a temp of at least 175.
The O2 sensor reads between .1 and 1vdc during normal operation. The lean condition would give you a consistent reading below .4. The thing I mentioned was checking for any exhaust leak. The manifold bolts are notorious for loosening and it is very common for the exhaust manifold cracking especially around the collector tubes. It is one of the most common reasons for a rich condition.
I am surprised you figured out how to move the ISA to adjust it. An old timer told me about moving it to set the TPS or I never would have figured out the trick with a 9v battery. If you did the adjustment the ISA must be moving in both directions.
I see your post says Mich. Where are you from?