If you have cracked the line from the cp3 that runs to the rail and don't have fuel coming out while cranking then I would suggest the following.
Start by unplugging the FCA,try to start the truck.If it start's then normally that means the FCA is working? Yes.Is it working correctly? Maybe not.
Something else you can do is take the FCA off the cp3,You do not need to remove the cp3 to do this.You will need to get a torqx "Spelling" bit to remove the FCA it is a size 25....There is 3 bolts holding it on to the cp3 they are not easy to get to but can be done.Once you have them removed wiggle the FCA out.
After it is out take two wires and hook them to your battery and touch the prongs on the inside of the FCA where it plugs in on the truck.It does not matter which is neg and which is positive.If you do this and the FCA doesn't "POP" then it is no good.
FYI take it easy on the bolts holding the FCA to the cp3 they can/will strip easy