8.1L 2500HD problems starting

GMC Sierra 2500HD is having problems starting up after running and stopping and starting a few mintues later. Today while parked with motor and A/C on it died twice. Took a couple of tries each time to start up. Battery is charge at 12.73. Belts seem to be tight as normal. Fuel pump does its thing when I turn it to start and then turn full way and just cranks. Generally its a warm day or truck is driven 10 miles or so and then it starts. Any ideas or things to try? Thanks for any help. I know that a few others have had problems with 8.1 but no answers for this.

had same problems starting with mine around 61,000 miles. Engine would not start after shutting down during a short warm-up, and would occasionally stall. Check your throttle body, mine was dirty and after cleaning I haven't had any more problems. A little spray with throttle body cleaner. I spoke with a GM tech about the problem (prior to discovering the dirty throttle body), and he advised to check the throttle body and if that did not solve the problem, remove both battery cables and hold them together for a few seconds to reset the computer. After startup, the computer will reset to proper operating conditions after driving a short distance. I did not need to reset the computer as cleaning the throttle body did the trick!

Turned out to be the Crankshaft position sensor. Took it to the shop and they couldn't find it until they left it running and checked on it 20 minutes later and it was dead. Thanks for your help.