If your engine is sound, you’ll probably find tune-ups due every year or so. This assumes that the fuel system is in peak operating condition. Generally tuning up your engine every Autumn and then again in the Spring is ample to keep your ignition happy.
ExtremeTerrain has Engine Tune-Up kits for most any Jeep year, make ad model. If you have problems finding yours, just call ExtremeTerrain and they will help you find the items you need to help keep your Jeep in top running form.