I have a 98 cherokee sport with the 4.0 motor and ever since i have owned it when the motor first starts up it begins to idle extremely rough and sputter and almost die. The motor continues to do this even while driving it feels as if it is going to die and I must put the pedal to the floor. Then after about 10 min it seems to go away. I have replaced sparkplugs, plug wires, distributor cap, and nothing has seemed to work. I have read on here that it may be my fuel sending unit and was wondering where I may be able to purchase one. I believe it may be the sending unit because when i put sea form that seems to help for that tank. Any opinions would be greatly appreciated. Sorry for the long post but I am excited to find new ideas on this site.

 

well glad someone had better luck with seafoam(mine straight up died and has run like crap ever since) as for the fuel pump not sure about the 98 whether you have to drop the tank or not but u can check by crawlin under there and lookin at the front of the tank to see if all the lines feed into the front , as for where to get it your local parts store should have it but chances are it'll have to be removed for comparison as when i ordered mine after the seafoam fiasco they had a few styles depending on tank size,engine,tranny and so on could also be a filter or fuel pressure regulator problem but im not sure where those are on the newer cherokees

 

I can't offer a solution, but I know mine does something similar from what you described. Certain times when I start it up it will run like crap until I accelerate and when I get close to reaching 25mph it will like backfire and I have to bury the throttle to fix it, after that it runs great! And other times when I start it I have absolutely no problems. It's just become something I have lived with.