i have a 2001 dodge cummings and it wont start. heres what is happening. about 2 weeks ago i ran the fuel down low and was having trouble starting the truck, but it always started. today i go to fill up (low fuel again) and it wont start, not even trying. i was thinking i ran the truck out of fuel. there is a relief valve at the fuel injector pump. i pushed this in while turning over the truck and was getting fuel. after i stopped cranking the motor i could hear the pump running for about 25 seconds after. fuel doesnt seem to be the problem, what else could it be.