I have a 2003 Tahoe z71 with approximately 125k miles. Lately, I've been having intermittent starting problems. Sometimes when I get in the vehicle and go to start it up, I turn the key to "on" and all the electronics come on as normal but when I go to crank it, nothing happens... no sound at all coming from under the hood, and the electronics all go out (which I think is normal) while the key I turned. I have to turn the key off and on and keep trying several times. Sometimes it takes 30 seconds, sometimes up to 10 minutes before the engine will crank... and when it does it sounds perfectly normal, not like a low battery or anything. I read on another board to check the transmission neutral sensor as it may be messed up and thinking the cehicle is in gear. It reads that I am in park, and I've even tried shifting to neutral and trying to start, but no change. Also, as weird as it sounds, it seems to have this problem mostly after the vehicle has been parked in the sun for a few hours. Not sure if its coincidental or actually related to the problem. Also tried using my spare key as the dealer said my key may be worn out... tried that but still have the problem. Any ideas???? Typed this from a phone so I apologize for any misspellings... thanks in advance for any advice.