I have owned my 1996 Jeep Cherokee Sport with the 4.0 HO for about four years now and there is one problem I have been chasing the entire time. Sometimes when cruising down the highway at about 70mph my rpms jump from about 2250 to 2500 or so. Sometimes if I floor the accelerator and then let off it will go back to normal. Or other times if I pull over and then slowly and steadily accelerate to 70 it won't do it. I have replaced the TPS, I have a new cap and rotor, new spark wires, new plugs, and I even did a fluid and filter change on the transmission. I replaced the fuel pump and the fuel filter. I have asked several people what my problem could be and mostly they just give me a dumb look. Can anyone help??

Oh I have also replaced both O2 sensors as well.

 

Check rhe condition and level of your fluid. Hopefully, it'll be rhat easy, of not, then I would thonk you're going to have to replace some hardware. Someone else should be along shortly that knows more about transmissions.

 

Sounds like the torque converter clutch is unlocking. Check the brake pedal switch for starters, should be tight up against the brake pedal arm, sometimes they back off a bit.
If the switch is OK, check the resistance of the TCC lockup solenoid once it's good and warm. 11-15 ohms or so.

You can test your TCC by cruising at a steady speed, 50MPH or better, then very slightly tap the brake pedal. You should see the RPM's jump up by about 300 momentarily as the TCC unlocks, then drop right back down when TCC locks up again