High idle issue

[gnozahs]

When I go to turn the screw to adjust the idle, the idle does not change at all. Currently it feels like it's turned all the way clockwise so I turned it a counterclockwise and the idle did not change at all. I warmed up the car, turned it off, disconnected the TPS, turned on the car, revved it to 2k for a while, adjusted the idle screw and nothing happened.

Idle currently sits at 1500RPM and when you rev it, it'll bounce from 1500-2000 a couple times and then stabilizes out at 1500RPM.

Motor is a KA24de 5 speed.

Also, it feels like the idle adjustment screw doesn't spin that much. It probably goes half to 3/4 turn in each direction and then stops. I didn't want to force it anymore and lead to breaking or stripping it. Is it supposed to have more adjustment than that? The screw looks like it sits in pretty deep already.

Steps taken so far:

I tried spraying carb cleaner onto all the vacuum lines and vacuum connections that I could possibly see and the idle did not change at all.

Checked the timing and it was at around 5 degrees. I rotated the distributor to the max and could only get it to 15 degrees. Idle of course went up and is at 2000 RPM now and bounces from 2300-2000 a couple times before evening out at 2000 when you rev it. I've also checked the distributor timing and it looked good. Rotor was in the 930 oclock range and cylinder 1 lined up to it with the crank pulley at TDC.

[compactfean]

Throttle body stop screw backed all the way off?