I have a 2003 Tahoe 4X4 and with just under a half tank of gas it will not start. If you add a gallon or so of gas you can hear the fuel pump pick up the gas and then it will start. What would cause this?:banghead: >

More than likely the pump is beginning to go bad.

change fuel filter then test pressure. be ready to dish out the bucks for a pump. test first it may just be a cloged filter.