I have a well kept 2007 Silverado NBS 6.0 with 87K miles. 6 month OCI, injector cleaner every 3-4 months, heated garage. A week ago it died while idling in a fast food drive thur. The engine would turn over, but it would not start. No CEL. It had to be towed home where after sitting for an hour it restarted. There were no codes found using a Scangauge II. The next day, it ran great until returning home and I let it idle in the driveway, and after 3 minutes it died. No CEL, No codes. It had to sit for 4 hours until it would restart. I then took it to my mechanic where after 2 days of running and idling he found no problems or codes. I took the truck back for a week and I removed and cleaned the throttle body hoping that would help. It just died again today after pulling into a parking spot at the grocery store. No CEL. It restarted only when I held the gas peddle down while cranking. I got it home and again , no codes. Any ideas? I`m thinking crankshaft position sensor. Thanks