I recently had my 4.0L pulled so i can redo the timing. All new chains, Sprockets, seals n gaskets. Upon starting the car, she sounded great. Nice smooth idle. When i drove her she would intermittently bog down then pick right back up.my mechanic said to retune it, since the battery had been out for awhile. So I retuned it and it helped slightly. She is more responsive like before the tear down but still bogs. It sounds like an over fueling issue. No idea, so any aevice would be appreciated.