the obd2 code for the misfire was a p0302 and p0304 i havent driven 100 miles yet or left the battery unplugged that long, it still seems to be running well, i just got back from being away for a few days and wheni went to start my jeep it took about 3 or so long cranks before it would turn over and start. could that just be because it was sitting?
Im having the exact same issue but for over a year now. CHeck engine light comes on and throws p301 misfire at #1 cylinder, but yet i detect no mis fire at all and she still runs fine, but recently within the past couple weeks when starting it starting take a lot more cranks before it starts up. Im thinking perhaps the crankcase sensor my be starting to go out, i dunno. Also, a mech said that the issue could be the camshaft sensor thats inside the distributor could be the issue. Heres meesage i got from him:
"a common cause of those codes on the 4.0 liter Jeep is a combination of the crank and cam sensors. When Jeep went to coil over plug ignition(the big *** assembly that bolts on over the plugs), they also started using the same little cam sensor synchronizer that always gave Ford such problems. That synchronizer can go to **** and cause the cam sensor to read incorrectly and count false misfires. Before the the switch to COP, it was the distributor that caused the same problem though you would generally get a rough idle. If yours has the dist, look for the shaft to be sloppy in the bushing."
"Same rule applies as to the 4.0 dist. and V8, Check the dist shaft for runout. The cam sensor is a wafer that sits between the dist housing and cap. These don't usually give us too much trouble and they're generally an all or nothing kind of thing. Still, if the dist shaft is okay, suspect the cam sensor. One more thing that can cause these codes on pretty much any application is valves. Carbon fouled or worn valve seats can cause an intermittent and random misfire. This always worse at idle though and you will feel it. One simple test for a worn or sunken valve seat is to run the engine at 2,000rpm for 15 seconds then release the throttle and watch for a misfire in the first 30 seconds after returning to idle. This is when the lifters will be pumped up and any valve(s) with excessive seat wear will tend to leak the most."
"Misfires can be weird. I've been in the business as a full time professional tech and as a master technician for most of the last 40 years. Just when I think I've seen it all and really have a handle on what can cause these misfires, I run into something new. Various degrees of valve damage and wear have been the cause behind many of these strange random misfire issues. Pinpointing the miss can be a real trick. I have lots of special equipment and generally just end up with the valve covers off, my leak down tester attached tapping the valve tips with a soft hammer and watching for the gauges to change. It's a real PITA."
Hope that helps. Im gonna replace the cam sensor, also know as the ignition pickup, and see if that helps the situation. Heres a pic:
Its under the cap n rotor.