my 2004 chevy silverado 4.3L 4x4 was running fine then it just died and wouldnt start i let it set there for 15 minutes and it started but didnt make it half a mile then died again and wont run.

Check engine light on? If so what are the codes?

I would have to agree with Js08016. First thing I would do is check your battery connection and wires first. and make sure you don't have excess corrosion or a broke wire.

check grounds and fuel pump relay, they get weak. but knowing more on vehicle helps? how many miles? how old is battery? (batteries are only good for the length of the warranty, then replace. so maybe 3 or 4 years tops. also GM has bad fuel pump ground problems, the ground to the pump.

Sounds like it may be the module in distrib. or may be bad ground wire in same area . sounds like a short by heat .(sml. Elect short )., will it stay running just sitting as long as ur drive times if they are same times or close see if it stays running if gas is poured in carb slowly. If not Elect, if so u could have cracked fuel lines thatwarm and expand just enough to alow air in an not proper amount of fuel pass or be pumped up. Pray this helps

To me it sounds like your crank sensor is bad