Originally Posted by
1project2many
There are only a few things that could cause repeated injector failure. Excess current through the injector could be an issue. If the ecm isn't limiting current when the injector is opened the injector coils can overheat. Or if you have a short to ground on the injector driver wires you could have momentary full current events. That's probably highly unlikely but still possible.
Fuel issues or fuel contamination can cause problems.
Does that throttle body have screens around the injectors? Are you using a fuel filter designed for an EFI system? Are you using fuel with greater than 10% alcohol?
Insufficient fuel circulation might allow the coils to overheat. I would think you'd have driveability issues before the injectors failed but if the pump is not able to produce significantly more pressure than the regulator calls for the truck could run correctly without returning fuel to the tank. I suppose one way to test this might be to go for a good drive then put your hand on the tank to check temperature.
Have you had any of the bad injectors tested? Understanding how they failed could be helpful.