2007 Chevy Silverado V6 Single Cab Classic
First off, I am not a vehicle expert, my apologies.
When I start my truck for the first time in the morning it starts up perfectly.
When I turn it off and start it again right away it starts up perfectly.
If I wait 3 hours...
4 hours...
7 hours...Again it starts perfectly.
HOWEVER, if I wait anywhere between 30 minutes to 2 1/2 hours when I turn it off to start it up again....it NEVER STARTS right. It sounds like something doesn't want to "catch". I can let the key go and something sounds like it is "turning" and when the start up finally happens it is extremely "weak", not "strong" like the essential morning start...it barely comes alive. AND IT ONLY HAPPENS WITHIN THAT SPECIFIC 30 MIN TO 2 1/2 TIME FRAME!!!! 
WHAT IS IT? WHAT IS HAPPENING? WHAT IS WRONG WITH IT?? I feel like all the weak, horrible starts are starting to wear down parts! SOMEBODY PLEASE HELP ME OUT!!
THANK YOU.