Coming from a Fuel Injection car theory, the idling is controlled by a Idle Air control valve with ECU inputs. The coolant temperature determines if the Idle Air control valve will open larger to let in more air (such as a cold start) or open smaller. The ECU controls the opening of the solenoid.
Back to the S10, which I have no knowledge on idling mechanisms, perhaps the way the ECU control the idling is through the butterfly valves (like my Versys 650) opening. In my car butterfly valves, I noticed it can get gummy and greasy and especially on colder days, these gummy stuff hardens and may cause a more severe sticky issues compared to warmer days. Did u notice more frequency during colder days? Throttle body cleaner dissolves this and I use it once every 20k km. I would spray generously on the butterfly valves, and into the orifices of the Idle Air valve.
It seems that these butterfly valves are sticky (high idling and erratic idling). I hope to learn more on the S10 systems once I get my new bike. Coming soon.