I've been experiencing some issues with my '98 Cherokee sport lately. It's got the 4.0L I6 in it, not sure about the transmission.
While accelerating after a warm ignition cycle the engine will "falter" and lose power and then sharply accelerate and then falter again and so forth. When it falters the rpm drops to about 1000, jumps to 2000 and accelerates and then falters again. When the r's are low it makes a kind of "tunk" sound. It does this until I get right on the gas.
My buddy's ford was having a similar issue and after replacing the fuel pump it hasn't acted up on him yet.
I'm thinking its something to do with the fuel system as I just replaced the plugs and wires.
Any insight or advice would be greatly appreciated

Thanks!

 

Verify your fuel pressure, With my own I had some weird issues like that after some trial and error (it never set any codes) I had a bad o2 sensor ( and a little corrosion in the harness plug). I replaced both o2 sensors and the thing runs like a champ.
Good luck

 

Sounds like a fuel problem, start cheap and replace the filter first and see if the problem is solved.

 

I am having the same problem to the tee. So i think that i am going to replace the O2 sensors and see where that goes. I really thought that it was the fuel pump and it still may be.

 

Start cheap. A fuel filter is a hell of a lot cheaper than an O2 sensor, and you can always justify replacing a fuel filter and that not being the problem. Try that with a $50 O2 sensor. Don't just start throwing parts at your Jeep, do some dianostics, or have a shop check it out. You'll be money ahead of the game that way.

 

I had my local mechanic take it down the road and he suggested that I replace the distributor cap and rotor first (tune up, I already did the plugs and wires) so I'm gonna try that and then move to the fuel filter and then the O2 sensors. I would think an O2 sensor or a misfire would trip the CPU into sending a check engine light though so I'm skeptical as to whether I should even touch the O2 sensors.

 

Well, the CE light tripped and the code was for the TPS. I replaced and it did nothing. About 3 weeks later it tripped again and the code was for the primary O2 sensor. Replaced it and she runs like a champ again. Thanks guys!