get a bottle of seafoam. put 1/3 of the bottle in with a full tank of fuel, and 1/3 in some cheapy dino oil. when the tank is empty, fill it up with only fuel, and change out the oil with whatever you regularly use. that night, take the remaining 1/3 you have left, disconnect a vacuum line.
get another set of hands to start the jeep up and keep the rpm's at 2000 while you SLOWLY let the vacuum line suck up the seafoam. the engine will want to stall so be sure you suck it up slow, and your helper watches the rpm's. once it's all in, shut it down for the night.
in the morning, fire her up. it's going to look like the jeep is on fire. I'm talking LOADS of smoke. it'll do this a good 15 minutes. eventually though it'll stop. that's it. nice clean engine
don't do the final part in a garage or your driveway. it seriously blows a sh*tload of smoke out the exhaust, and it leaves a nasty black stain wherever the Jeep was sitting.