I have an 03 Duramax now with 101000 miles on engine. I has given me starting trouble when warm for the last several months. Cranks, won't start. In the AM the primer pump may work. I just finished putting out 4 grand to our local GM dealer for a new pump, & new batteries which took seventeen days to order and install. Not a happy camper! I think I still have the problem, I will know next week when on my calls.