1998 Other Jeep Models sputtering and hesitation, intermitte

Vehicle inlast 3 wks started sputtering during engine warm up, which leads to irractic idle, may last for 1-3 min before clearing out, DOES NOT DO THIS EVERY START, then while under power it MAY start hesitation with misfire popping back through throttle body, playing with throttle because it feels that it may stall, then it will completely disappear and go like bat out of hell, may be the only occurance that day, or may do it 2-4 more times that day, acts like water in the fuel, so far I have treated 4 tanks of fuel with isopropyl at double strength, changed crankshaft sensor, camshaft sensor, plugs, wires, cap, rotor are all 2 yrs old with less than 15k mi on them (platinum plugs) and look to be good shape, fuel pump assy was changed 4 yrs ago probably 25-30k mi on it, throttle body was cleaned with carb and choke cleaner 1k ago during oil change, was quite dirty, is does seem to have o rough idle, slighty more pronounced than usual but this moyor always has since purchase, had 80k when purchased, any guesses any one?