Mercury, Tracer, 1995, 93,000 miles.
With the start of cold weather, idle speed hs gone to appox. 1500 rpm. And never gets any lower. Before cold weather when the car warmed up, the idle would go to about 750 rpm. I did notice yesterday, however, when I got gas, when I restarted the engine the idle went to 750 but resumed the higher idle speed shortly thereafter.
I have a pretty good grasp of the symptoms, I just don't know what parts to replace to fix it.