My friend has an 03 Tahoe, says the vehicle won't start unless the gas tank is half-ful or better. Says when it won't start, he can add a few gallons, then he can hear the pump run and it starts. He said at least once, he topped off the tank, just to see how many gallons was in it, when the problem occured. According to the gallons added, he had almost half a tank when the problem happened, and it seems to happen regular.

I told him, it sounded like a fuel pump issue to me or the wiring circuit. I didn't think to ask him if he could hear the pump run on the initial prime. I told him the pump should run even if the tank was empty.

Any thoughts? thanks

 

Your're probably right.
Try the fuel filter first if it hasn't been changed within a year and if that isn't the cure then it is most likely the pump.