I don't have to post here much since my truck is a little older and I can normally find an answer with the search but not this time. 2007 NNBS Sierra crew 4x4 with the 5.3 flex that just hit 100k. For 6 months now I turn the key, let it go and the starter spins for the 6 or 8 seconds it's supposed to but it doesn't start. Second crank it starts. 95% of the time this is what happens and 5% of the time it will start on the first crank like it's supposed to. It's not the fuel pump or fuel pressure. I can cycle the key on and off 12 times before I try to start it and the same thing happens. Since this has started happening I have lost about 2mpg in addition. The truck does everything else like it should. No power loss or hesitation in the motor. Any insight would be much appreciated!