So my 89 Cherokee has been running like crap for a couple months now and I cannot find what is wrong with it. It starts up fine then after it is warmed up it starts to hesitate and stutter when I have to accelerate. I have changed the spark plugs, O2 sensor, fuel pump, and the cap and rotor. Does anyone know what might be causing this problem? The hardest part is this is my daily driver also and cannot just park it. Thanks guys

 

I have a similar problem with my 90 XJ. Mine developed the issue after I MIG welded the exhaust. I forgot to disconnect the neg battery terminal so I assume its a fried sensor. I replaced the entire ecm and also the O2 sensor. Neither cured the problem , so I can atleast tell you its probably not the ecm. Could be a clogged cat? If you figure it out let me know!