Do NOT run a higher octane grade gasoline, that could and likely would just make it worse. 87 octane gasoline ignites faster and far more easily than 89-93 octane fuels do which are purposely made to burn slower and be harder to ignite. True.
Do you tend to drive your Jeep exceptionally conservatively, never (or hardly ever) revving it hard to high RPMs? If so, that will cause carbon to build up inside the combustion chambers. A good way to clear that out is with the age-old "Italian tuneup" which is nothing more than driving it super-aggressively over a few days... when safe accelerating hard to high RPMs using wide-open throttle. That is what commonly happens to high-performance cars whose owners are afraid to drive them aggressively enough and is how most mechanics fix them.
There's another method to get rid of carbon that is done more often than the Italian Tuneup since it can be done in just a few minutes without driving aggressively. This may sound scary to a novice mechanic but done properly, it is highly effective and has been in use since WWII when aircraft mechanics discovered it. With the engine running, SLOWLY and CAREFULLY trickle (!!!) 12-16 ounces of water into the air intake while the engine is running. Slowly enough that it will take probably 2 minutes to empty the water container. Keep control of the water container, you don't want to accidentally dump the full container in all a once which would hydrolock the engine.
Keep the RPMs up as you do this because it will cause the engine to stall if you don't.
This causes little micro-shockwaves inside the combustion chamber breaking up the carbon deposits and blowing it out of the engine through the exhaust system.
I don't want to read any whining about this process from those it scares. It works, works fine, and will get rid of carbon deposits quickly and easily without any harm coming to the engine.
By the way, here's how it was discovered during WWII... to help heavily-laden bomber aircraft climb to high altitudes over Europe, water injection was added to the bomber engines which substantially increased their power. Once this started, mechanics soon noticed the engines were sparkling clean inside with no carbon deposits. This is still done to this day in some engines and some aircraft engines including jet engines.