What could cause the fuel getting to the throttle body but none at the injectors

Yes. It will run if I pour fuel directly into the throttle body. After doing this, the fuel injectors would drip a little fuel at the next priming cycle, then completely stop again. It was running just before the simple changing of the filter in the return line. The pump was replaced two days ago, so it is new. Also checked to make sure the filter flow direction was correct and it is hooked up correctly.

In that case injector pulse 'should' be ok BUT needs to be tested..along with fuel pressure so you know where you stand! Have you checked flash codes?.. Key on.. Off .. On .. Off.. On. and watch C.E.L. flash out any possible codes??

Out of ammo!!

I'm out of ammo!

Fuel pump is new, installed two days ago. Drove the truck to get the new filter. No codes and if I hold a finger on the bottom of the injectors I can feel them opening.

Ok..... Assume.

The fuel pressure regulator is located on the side of the throttle body. It was working but now fuel is not passing through it. Could the regulator be defective even if I can push it open with an awl? That seems to be where the fuel is stopping. I've never had a regulator fail by requiring MORE pressure before but is it possible?

Did you ever get it figured out? I have the same problem