K, after many months and inspections here is what I found out and think has solved the problem. I found out that my fuel filter had some leak mark on the two ends of it. So I cleaned up the mark and retightened the nuts. The stall stopped for about few months. Then one stall about one month ago. I found out that one end for the fuel filter still wasn't tight enough. No stall after the re-retightening and no leak mark so far. Recently I cleaned the throttle body and the spark plugs. That make the idle and acceleration smoother. Only one more thing to do: differential mount. Just need to figure out how the makeshift tool for replacing the mount that ppl are talking about works. Thanks