Idling HIGH

I have an 88 Tercel and the engine has a high idle. I know theres a way to turn it down but I just cant figure out how. Anyone have any comments about this matter?

p.s. Its not constant. Sometimes its high, sometimes its not (but most times high).

My 87 Tercel did the same. With a little wd-40 it was fixed. The problem was a sticking choke.

also check for an intermitted vacuum leak and choke linkage.