You idle air control valve is having a problem as well as carbon build up in the engine. Part store chemicals won't event make a dent in the carbon. Go to your Ford dealer. It will cost about $500.
Sounds like the fuel pump is clogged.
The start-stall issues are most likely the result of the car being 23 years old and in dire need of an overhaul.
put new injectors in
If a 1999 Ford Range starts rough and wants to stall if not given extra gas, the fuel filter might need changed. If it becomes clogged, gas can not get through.
torque converter is hangin up..
WXYZ is a trapezoid......
Rule of thumb: Open needle valve 1-1/2 turns and start the engine, let it warm up then slowly rotate needle valve clockwise until engine wants to stall then rotate needle valve counterclockwise until engine wants to stall. Set the valve in between the two extremes and fine tune from there for best setting.
Check for a vacuum leak
If the rpm's are erratic it could be the throttle position sensor. It is a cheap and easy repair.
check your fuel pump.
Engine temperature sensor? Vacuum leak?
It sounds like a loose connection somewhere between the battery and the main distribution.