1999 silverado will not start

i have a 1999 silverado with a 5.3 v8 in it the truck will fire but then dies right away i have 55lb of fuel pressure iv changed the crank shaft sensor the camshaft sensor mass air flow sensor the map sensor and the fuel filter ive had it on 3 scanners and it is not giving any codes if anyone has any idea what is wrong i would appreciate any feed back thanks ryan

my body has the same truck and his did that and hey said that they are know to have sending unit problems he changed that and it fixed it

is it the nbs 99 on mine i had a fuse on the end of the dash that would blow every once and a while it was the bcm fuse and it would crand and die and wouldn't start or it might be factory security

i had the same problem with my i was at work when it started its starts then it dies its not your battery well come to find out it was my factory security it showed like some one was tryin to steal it it happend like 6 times dont take it to the dealership they try to charge me $1000 too see whats wrong with it then fix the problem look at all your fuses first if nothing is blown then take it to the electric shop. does it die all the times you try to start it if so then it is the factory security i hope this helps you a little with your problem