There are a large number of possibilities.
Try these....
1. When you start the truck, pull the throttle out so the truck will idle @ 1000rpms. A LOT of my trucks will die after you start them if the throttle is not pulled out.
2. The glass fuse for the fuel pump could be burnt out. Your injector pump will pull fuel from the tank, but if the filters are dirty, or if water needs to be drained from the filters, it could cause the truck to stall.
*** to check if your fuel pump works, you can simply flip the accessory power to "on"....then go around & listen inside the fuel tank for a humming sound. If you hear it, it works. If you dont, the pump is bad or the fuse is burnt out. ***
3. The injector return lines could be leaking & allowing air to get mixed with the fuel. They are the little 2-3" lines that stretch from one injector to the next. If they are wet, they are leaking. VERY easy to fix.
4. FILTERS
I am sure it is something simple. Its just a matter of figuring out which one of these is causing the problem. I am betting on the throttle.