High idle, then hunting idle

[searanch]

Greetings: My first post!

I have a '95 Swift 4dr 5pd with 1.3L 8 valve motor.

A few months ago my warm idle speed moved to 1300 rpm.

Now, about a month ago, my warm idle speed started hunting - or cycling - between 2000 and 1000 rpm, at one second intervals, very regularly, but only while the car is in motion. As soon as I come to a full stop, the hunting cycle stops within a second and the idle settles back down to the 1300 rpm high idle it adopted a few months ago.

Two separate problems, one on top of the other? Or one problem that's developing?

I have unplugged the connector to the idle air control (at least that's what I think I've unplugged - under the air filter, on left side of throttlebody, as seen from front of car) and the idle jumps to 2000 rpm and stays there. There is no hunting/cycling while in motion, presumably because it's already up at the higher idle that the unidentified component is wanting it at. When I plug the connector back onto the idle air control sensor/valve/motor, the idle settles back down to 1300 (and the hunting/cycling comes back when in motion).

Help. Any suggestions from the collected wisdom here? And what is this mysterious connection between my cycling idle and the motion of the vehicle? Is there a sensor that indicates rolling wheels and feeds that data to the computer? Is this a key or insight into what component is failing?

Thanks!!