I was driving home from my parents house going about 70 down the highway fourth gear about 2700 rpms. All of a sudden my jeep hichups and the speedo dives to like 45-50 it then climbs straight back up to how fast i am really going and everythings fine...it did this several times and i don't know what it is. It feels like i hit the govener but going 70....i've 105 in it and i didn't hit that thing. It also did it in third and fith a couple days later, and another thing it is dyin on me if i let it idle for longer than about 4 minutes in the driveway? any suggestions. thanks hag