With engine running, crack the fitting at the top of the dry injector and see if fuel gets up there. Don't worry, it would just dribble out. The return hoses couldn't stop fuel flow since pressure could build to >1000 psig and the hose would pop off with 5 psig. If air filled the tube, I would expect it would eventually be swept thru, but never tried.

If no fuel, something is wrong in that circuit in the injection pump. First, remove the delivery valve and inspect the internal elements. Take many photos to not mix up assembly. It is basically a check-valve, so if it doesn't seal well, the output may never build pressure. Hopefully, you find a little piece of junk blocking the valve seal.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans