Recently I have been having an erratic idle after starting my jeep. It'll start fine and idle for a minute or two ok, then the prms will drop like it's not getting gas, then kick back up to 1200-1500 rpms then drop back to 1000 even for a few minutes. then I'll be driving along fine and it will start doing this while I drive. When I give it a bit more gas it hesitates and then surges back to normal. but it seems like it has been getting worse. It does it less with a full tank of gas. I have run gas treament through it,, also dry gas, still no luck and it started doing this all of a sudden. It first started with the rough idle, then the hesitation during driving kicked in. Any thoughts?