3.0 v6 XLT '89 Ranger

When disengaging the clutch or in neutral the RPM's go up to and stay around 3k until my tires are completely stopped. Once I come to a complete stop the rpm's go to normal...if I was to start passively rolling the RPM's go right back up to around 3k?

Dealership changed the air intake sensor, this did not help the problem. This problem happens 99% of the time. Once in a while it will not happen but then the next stop sign or light it will happen again.

I cannot figure out any pattern to when this happens and when it does not.

Thanks for any help.

 

My initial thoughts would be a problem with the idle air control valve or the throttle position sensor.