Truck start then dies

The first thing I would check is low side fuel pressure/volume. Also, check the operation of the fuel tank switching valve if you have dual tanks.

Capacity (Volume) Test

1. Disconnect the fuel line at the fuel filter (fuel line is pressurized).
2. Place a container (1/2 liter or 1 pint minimum) at the end of the disconnected fuel line (a piece of hose may be needed on the fuel line end). Crank engine ten seconds. The fuel pump should deliver 1/3 pint of fuel, or more.
3. Perform pressure test if fuel flow is to specification see specifications.
4. If fuel flow is low, repeat test using a remote non-breakable container of diesel fuel. Remove fuel hose from fuel pump inlet supply line. Connect a length of fuel hose from the fuel supply line to the non-breakable container and repeat Step 3. If fuel flow is to specification, the problem is either a plugged fuel/water separator or, a kinked or leaking fuel hose. Service as necessary.
5. If fuel flow does not meet specifications, replace fuel pump.

I hope this gets you started. Please let us know if we can be of further assistance.