Well my 98 ZJ with 150k on it started doing weird things. So from time to time when i pull up to a stop sign or lights and i keep it in gear, the idle starts going crazy and acting like its going to die... Then when i try and go, it acts like it doesn't have any power and kind of clunks along. So normally i put it in neutral let the engine get back to normaly (couple seconds), make sure that it revs okay, and then put it back in gear and it goes again like normal.. Not really sure what the problem is. I tried replacing the spark plugs and that didn't really do much. The motor never actually dies during this though. So every time that i pull up to stop now im just throwing it into neutral. Any suggestions of what it could be? Oh and its the 4.0 straight 6 and its in 2wd when it does this.
probaly wont help but have you tried to unhook batt for about an hour to re program ecu back to stock ,,probaly not the prob but its free and ive seen it fix some wierd problems before also this will get rid of check eng lights and so on ,,,good luck man,