Need some help if anyone can offer it. The truck is a 2002 2500HD Chevy Silverado, 6.0 gas, 150,000 miles. I just recently started having a problem when starting it up. The truck will crank as normal, no odd cliking sound, or grinding, or any strain to crank. But, with the first turn of the key, that's all it does is crank but doesn't tuen over. If I turn the key back to off and crank again it starts right up with no problem. Now that it's started I can turn the truck off, crank the key forward and it fires right up no issues at all just like normal. HOWEVER.........if the truck sits for say, 10-15 minutes or more, the same issue occurs where it will not tuen over but just crank until I back the key to off and turn it again and then it starts. Does thuis sound frustrating or what? I went to Advanced Auto and had the battery, alternator, and starter tested and everythig came back normal. The test did say the battery could use charging but the employee said that it wasn't low enough that it would be causing this issue. I am attaching the test below so you can see exactly what it says. My battery is just under 2 years old, I think December 2011 is when I got it. Now I thought maybe I had gotten some "bad gas" about 2 weeks ago. Right after I put gas in the truck is when I started having this issue. Coinsidence? Maybe, but I'm not sure if it was that or not. Just in case it was, I let that gas go until my gas light came on. I went to a different station put in half a tank of 93 (which I usually use anyways) and put a can of sea foam in the tank. After that the truck started fine like 2 times and then back to the issue. I let that run through, put in another half tank of 93 and sucked half a can of sea foam in though the brake booster line (main vaccuum line) let it sit for 30 minutes. I then went out and drove it hard, getting the RPM'S up really high. Still the same problem afterwards. On Wednesday I put in a bottle of that Star Tron enzyme fuel treatment which I use i all my lawn equipment and the stuff is good. Star Tron Enzyme Fuel Treatment - HOME So after that, I have run about a 2/3 of the gas out with the start tron treatment and still have the starting issue. Just happened this morning and I am really frustrated now. I can't figure out what is causing this and it's bothering me. It's not a "huge" issue, but the fact it's happening is embarassing when out anywhere and the truck just cranks but doesn't start and I have to crank it again. The one thing I do know is this; it only happens after the truck has been turned off for 10-15 minutes or more. If the truck gets turned off and right back on or off for just a few minutes and then back on, it starts fine. What is involved in the process of staring this truck where time is involved? Almost like fuel isn't where it's supposed to be when cranking because after sitting it's leaked back down to where it's not supposed to be. Not sure if that makes any sense or not. Is some type of pump not pumping the fuel to where it's supposed to be with the first crank and then turning it off and back on gets it to where its supposedto be? Not sure if that makes any sense either. If I keep the key turmed forward and keep cranking and cranking, it starts sometimes. Other times I have to back it to off, crank it again and then it turns right over as normal. I replaced the plugs and wires 2 years ago as well as the battery. The starter and alternator are original but tested fine the other day. What could it be? Anyone that can help me? Here is the test from Advanced Auto 2 days ago.