89 Taurus

I am having an idling problem. Sometimes it idles so high I have to hold the brake down real hard and sometimes when I’m at a complete stop and the compressor kicks on it goes dead. Worse in cold weather on dying. When you crank it, it just takes off.

Worn and binding throttle cable. faulty Idle Air Control Valve problem, or possibly a transmission throttle cable hanging or out of adjustment. I’m reasonably sure this model still used a transmission cable.
The cables are self-adjusting and this could be checked by disconnecting the cable at the throttle body (trans cable, not throttle cable) and see if the idle returns to normal.

Another possibility might be the ignition timing being too far advanced. This era of Taurus could really act strange if the timing is off. There is no reason for it to be off but if the distributor, ignition module, etc. has been dinked around with then it’s entirely possible. They’re pretty touchy.

In addition here’s something from my daughter’s old taurus with high idle.
We found ( after all of the above from ok4450 ), at the nose of the upper intake plennum where the throttle position sensor is / where the accel cable goes to and is spring loaded, that the metal intake butterfly inside became worn on just one side ( from the spring tension ) leaving a crescent shaped opening . - miniscule but there.

Resulting in a ‘‘never all the way closed’’ situation that the idle air valve doesn’t compensate for, hence, high idle.

I custom built a new butterfly from a piece of steel as the OE is not offered by part number.