My truck has stalled twice in last 3 weeks. It is runnig fine then just stalls out. First time I was able to re-start immediately. Second time it took me 1/2 hour to re-start. The truck and shift shook violently while trying to start and would not start. Then it did after half-hour and ran fine again. Checked for codes both times - no codes .....Replaced fuel filter after first stall...guess it did not work because it stalled second time. Any ideas ????