i have owned my 2008 silverado lt with 5.3 for a couple of years now. since i bought it there has been a 6 second delay in the start procedure. when you turn the key to engage starter you must hold the key in this position for 6 seconds and then the starter will engage and the truck starts normally. the previous owner says he has had it in several shops and none of them was able to tell him why. i am wondering if it has something to do with the anti theft system. But honestly have no clue what causes it. anyone have any ideas what this may be from?

 

probably some aftermarket device wired into the system. Leasing and loan companies put starter kill boxes in so they can disable vehicles when buyers stop paying. start at the ignition switch and look for any aftermarket wiring that leads to a module. ie black box