I have a random miss at idle and at higher RPM. I have new plugs that were gapped . The distributor is new as is the cam sensor in it . The plugs weren't very old but i plan to replace them since I ripped one apart when it wouldn't pop off the plug while I was playing with things on my day off . The ignition coil is basically new . The fuel pump is new . All my grounds are new and all cables are oo- Guage aftermarket kit . All the sensors on the throttle body are new as is the cps. It starts right up runs ok then progresses to run poorly as it continues to run . Fuel in tank was drained out and fresh fuel put in . Vaccine lines seem good . Engine has 98k on it . I bought a borescope , compression tester and despite some ignition parts being new I bought a complete tune up kit with performance ignition coil these all should be delivered before I get home on my next day off ...lol... Any suggestions . My 4.0 is a 99 pre coil pack which should be obvious since it has a dizzy . I'm also noticing all 6 plugs look to have rather immediate carbon fouling it doesn't look like oil but I can clean them run the jeep and they are immediately dirty ...lol...I'm really not looking forward to pulling a head ;-)