I wish I could feel comfortable saying it was the gas. I know it is more than likely not though. The car revs up to 2K just fine, but slows down to a snails pace after that, higher rpms are not AS MUCH of a problem, but still not where I remember her. I have driven her over 130mph before with no problem, but now getting to just 80mph is a problem.One word: "Stabil"
All is good there, rock steady idle, no misfires, all new plugs and wires.Are you sure it is firing on all 4 cylinders? Remove one spark plug wire at a time and see if the idle speed changes about the same each time. If you find one that doesn't seem to drop as much (or at all) then you may have a weak or dead cylinder. If so, you need to investigate why. Each needs air/fuel, + compression + spark (at the right time) to make full power. If one cylinder isn't doing its share then one of those things is off.
Last time I had a connection problem on the AFM, my check engine light came on. Is the 1986 AFM the same as a 1990?Have you figured it out yet?
Try unplugging the connector to the AFM and see if it makes any difference. It should run much worse unplugged. If not, that'd point to a problem with the AFM or its connector. Try the same with the TPS.
Here's some info about the Bosch AFM: click on AFM in the left side bar