This is a common problem with all 94-02 Rams with gas engines, not just the V10. Your fuel pressure regulator (located in the gas tank with the fuel pump) is not holding pressure in the fuel injector rail so after your truck has sat for a few hours (or minutes depending on the condition of the rest of the fuel system), you have to do the double key dance like all the rest of us. The first crank repressurizes the fuel rail, the second crank then has fuel readily available to use to start the engine. You have two options: replace the fuel pressure regulator or live with it.