Have you seen a check engine light? If so, gotta pull the codes for clues/guidance.
If you don't have a CEL, I'd start by first ensuring you have fresh spark plugs (I like NGK copper plugs gapped to .035 for your vintage) and testing your fuel pressure.
For your 00, you should have 49 psi at idle. If you don't have access to a fuel pressure gauge, they can be rented from many parts stores; call around.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!