My 6.0 has done this for 3 years. After sitting overnight it will start right up and die twice as if I turn the key off. On the third time it will start. Once it starts it will run start right up all day. I just installed all new OEM parts. Heads, injectors, hpop, oil cooler, engine oil pump, water pump, icp, ipr, eps, upgraded blue fuel filter kit, complete engine and injector harnesses. Still does the same thing. 2 years ago a Ford mechanic said the fuel pump was going. I replaced it with new fuel pump, still had the same problem. On my Modis, ICP jumps to 680 psi in 2 seconds after sitting. I let it sit overnight and removed the fuel filter cap, the housing was empty. Purchased another new blue kit again. Still doing the same thing. It is loosing prime somehow. No idea what to do next.