So it is retracted in both the crank and run positions? Be sure of that, as mentioned, they fail in the crank position most often.

If you are beyond that, have someone crank it over while you crack the lines loose at the injectors, should see fuel get pushed out. If there is bubble's then it lost its prime for some reason.....no fuel...then keep going backwards in the system.

Try to prime the system using the manual plunger at the mechanical lift pump. See if it pushes fuel at the canister filter using the plunger.