2001 silverado 5.3 motor issues

Hi i'm new here and my truck has an issue as to when i start it usually after its been sitting for at least a couple of hours that it will jump to life and then die. as if its not get fuel and ill crank it again and it will seem as if its getting less fuel. then if i turn off the ignition and pull the key out and wait for maybe 10 seconds and try again it will start normally. Any ideas to what this may be?