Jeep Cherokee 1999 4.0 liter problem starting

I have a 1999 Jeep Cherokee 4.0 liter with 445000 miles on it. In the morning my car starts fine. After driving it for a while and my engine warms up my Jeep starts to have problems starting. It will turn over and over. Sometimes it'll start but start real rough or ill have to turn it over while pushing the gas pedal all the way down and it will finally start. Has anyone else had this problem with their Jeep Cherokees??