My 2500 started stalling out when it hit half a tank of fuel. Didn't sputter, just died. It doesn't have an in line lift pump, just the in tank pump. Replaced that, as that was what diagnostics where indicating was the problem.
Still does it. Any suggestions on what else to check? My mechanic is stumped.

 

check fuel pressure and rail pressure when you have a full tank, and again when you have the issue come up.

 

When it stalls out, does it restart right away? Does it keep stalling? Can you hear the in-tank pump when this is happening?

Sounds like maybe there is a crack in the in-tank module (or a line in there) that is causing it to suck air when it drops below half a tank. Or something. I'd be pulling the module out and giving it a good looking over - AFTER checking fuel pressure.

Don't be silly Jigabop, who has a 30,000 psi rail pressure gauge lying around?

 

Once it stalls, it is done. Won't start again till you put fuel in it. Which is why we thought the in tank pump had a crack or something. So we replaced it and it still does it. Put the in tank pump onto a machine that pumps steam through and it didn't appear to have any cracks, although the float had wore through and had a hole.
I can't hear the pump, but I can't hear it normally above the sound of the engine.
I was having trouble starting it, in fact still do. It's more than just the injectors, needs to have the block heater plugged in even at 50°F, computer is suspected, although it had coded that one of the air intake heater relays had quit. I changed that and problem still occurs.
I'm at the point where I'm reluctant to keep throwing money at it.
This is what I got back when I got diagnostics done, before it started stalling at a half tank.

 

Inspect fuel lines & wiring front to back both supply and return. Something weird is going on. Get a fuel pressure gauge on it and monitor pressure. When you turn the key the lift pump should cycle. You should be able to hear it with low ambient noise, have someone else turn the key and stick your ear to the filler neck with the cap off.

If the lift pump isn't coming on - blown fuse, bad relay, chewed/torn wires - the CP3 has to suck fuel through the lift pump and alk the way through the lines. It may very well be that at about half tank the injection pump cannot suck enough fuel.

But if that was the case I dont know that the fuel pressure gauge would read at all on the supply side.

Is the evap vent solenoid opening? Does it have a vent solenoid? When it stalls at half tank, can yoh jump out and open the fuel cap and see if the tank is in a vacuum? Will it restart after venting? Or just leave the cap off and see if it ever stalls.

The injector return overage is curious too. You may have a couple of issues.

 

This may be obnoxiously obvious, but have you changed your fuel filter and drained the water separator recently?

 

I change the fuel filter at every oil change, so that I don't forget.
I will check what I know how to and get a mechanic to check the rest. I have had to learn a lot about the insides of my truck since getting this one. All my other Dodges have been excellent.