Another idle problem
 

I have a 86 N/A 5spd, engine is fairly fresh about 10,000mi, was rebuilt by a Mazda mechanic before I purchased her. He was the previous owner. I have owned this one for about 2 yrs and has always had this problem, I bought her during warm weather.

First, when I go to crank her (cold engine), I have to pat the gas for a minute or two to keep running, no problem. During warm to hot days it goes to 800 rpm like it should, engine temp is normal.

Problem is during cool mornings or cold days it idles up to 1800 rpm and stays there all day, until the outside temp gets above 65-70 deg. F (18-21 C)., engine temp is normal.

thanks for any help.