87 2.5L Fast Idle

My 87 Jeep Comanche is idling fast. It idles at regular speed when cold, but as it warms it idles faster. The specifications in the Haynes manual for all the sensors reads that the voltages and resistances are for 91 and newer models, with no specifications for older ones. This is a TBI 2.5L I know there are no vacuum leaks as I have tested extensively with carb cleaner. My TPS has a reading of 400 mV at the low and 4.8 V as a high. It smothly adjusts as I move it. I adjusted the screw on the idle adjustment motor and now I only idle at 2500 rmp instead of 3000 all the time. I know that this motor is not extended outwards (speeding up the idle) any further then it is at rest with the engine running. Please any suggestions would help.