1996 Sidekick revs on its own when holding the gas pedal at about 2000 rpm

[sunrise7]

1.6 Liter, 5spd, 4wd, 93,000 miles on odometer

Weird symptom.  It's hard starting when cold, but once running and warmed up, if you hold the gas pedal at about 2000 rpm the engine will start
 to rev up and down between approximately 2500 and 1500 rpm.  If you depress the pedal some more it will stop the cycling and hold at higher rpms.
Its only at about 2000 rpm where this cycling happens.
Car runs fine on the road, even at speeds to 65mph....
Does smell like it runs rich, but it runs....

Any ideas as to what it may be? 
Something clogged in Throttle body?
Throttle position sensor issue ?
Idle air control valve malfunction ? 

Thanks......