Idles fast & Slow by itself

I have a '94 Tercel auto. The thing kinda runs well however recently it will idle slow then rev up slightly ( no tack ) then back again. It has been doing this off and on again for some time. Further and more recently after its warm it wont start.

HELPPPPPPPPPPPPPPP

check for vacuum leaks first.

Check to see if your vehicle has an idle speed sensor. Possibly mounted on the throttle body or somehow connected to throttle cable. Had a firebird that was doing the same thing and that was the problem. Steve