Idle won't come down, Adjusting the TPS seemed so simple Options

[ThinAir]

1973 2.0 liter with stock FI

It's been running and idling fine, but I've had a few hesitation issues so I decided that I would check the calibration of the TPS. First, I cleaned the TB, including making sure that the air passages were clear. Although I accidentally moved the idle screw a bit, it wasn't enough to worry about and I just expected my idle to need a little tweaking if it wasn't right.

I checked the TPS position with my ohm meter and also using a continuity tester (a trick I picked up from Gary Cotton on YouTube). I've done this procedure before as well as changed the circuit board and I didn't experience anything out of the ordinary.

After reconnecting all the vacuum lines and the throttle cable, the engine started right up, but idled very high. I tried closing the idle air screw, but the best I've been able to do is to get it down to 2000 rpm. The engine is warmed up enough that the oil temp needle is up from the bottom so I don't think it's a situation of a cold engine condition.

Any ideas what could be causing this? The TPS did end up in a different position by about 1 mark, but I've checked it several times and it appears to be properly adjusted.

When I had the TB off the engine, I looked through the various passages. I noticed that I could see a ball at the end of the idle air adjuster screw and it looked like there was space for it to move. Should I be able to completely close off that passage by turning in this screw or does it have a "stop"?