If I may, I would throw in my 2 cents. I am not an expert, but I went through similar struggles, so may have some practical observations. Every time I had issues (missing, hesitating, plugs with gas on them, getting a bit better on higher rpms, well she is still missing, you just do not feel it) after longer (few months) sleeping time - it was always the same: one of the plug connectors. I had Beru connectors, then one by one in the circumstances as above I replaced then with Bosch ones and the issues went away.
From your description you may indeed have your car tuned too rich anyway, but that is another story, perhaps, not causing the severe symptoms you describe, I am not sure.
But before getting to the FIP complicated issues and injectors, I would perhaps suggest:
- wait till it is dark in the garage, start the car, start the engine and check if you see any blue lightnings around plugs
- you can also get a thick glove, insulated pliers and, while engine is idling, remove connectors from plug one by one - where you hear the change of tone of engine - that cylinder is working, when pulling connector does not make the change - this cylinder is not working; I would start from cylinders that ha wet plugs when you checked them
If you decide to go the fuel way, if I may suggest, before you fill the tank with fresh gas, I would do the simplest tests:
- the fuel flow test, checking the rate at the end of the return line
- if bad, I would change the filters and do the checks after each one, starting from the easiest: main filter, fuel pump screen, tank filter (this may be tough to undo and also - you have to have your tank empty)
These are the practicalities I thought I would share