1995 Jeep Cherokee has very low idle RPM?

I have a 1995 Jeep Cherokee with the 2.5L 4 cyl, for the last 3 months or so the idle RPM is very low. If you go 2 or more days without driving the car it will start but die unless you give it throttle when starting. It seems to get better when you drive it. After driving say 10 miles it is somewhat normal RPM, But after you turn it off and wait an hour it is back to the low RPM. When I disconnect the battery and reconnect it, it idles fine for 10 or so minutes. I don't have a RPM gauge so i cant tell you exactly what numbers I am at but i would say 200-300 RPM. Some time when I go to push the throttle down hard it will miss the combustion in the chamber.