92 Wrangler 2.5 Idles at about 2,000 RPM. When driving I will let off the gas and the engine will keep accelerating, Ill push in the clutch and the engine will rev to about 3,000 RPM then drop back down.
Could be a broken Vacuum line or bad Throttle Position Sensor. Visually inspect your vacuum lines for any cracks or rotted rubber boots.
The TPS can be tested with a voltmeter. At idle, probe the center wire. The TPS should read no less than 200 millivolts. The voltage should gradually increase as the throttle is opened to a maximum of 4.8 volts at wide open throttle.
You don't need to go all the way to WOT. Just to around 3500 rpm is enough to check if the sensor is working or not.