I have an idle issue or something. After starting my jeep idles a bit high but s

What is your question?

Jeep idles high but steady. Longer it worse it gets. It stumbles or bucks when pressing gas pedal. Also driving at steady speed it stumbles . it has died a few times as well. When cold it runs mostly fine. When it warms up is when it gets bad

What makes this problem better or worse?

Its worse after warming up and running for awhile

How long has your 1999 Jeep Grand Cherokee had this problem?

Few weeks