Bleeding Yanmar 2qm15 injector pump

[Le Blurr]

I recently replaced the fuel filter and attempted to prime the system. One cylinder/line primed no problem, up to the injector, however, the rear line coming out of the injector pump won't prime. No fuel comes out with the manual lever, or when turned over with the compression levers opened. Is this a problem in the injector pump? I've looked everywhere for what could be causing this and it seems to be a unique problem. The fuel shut off appears to be fully disengaged, and the motor ran fine before changing the filter.
There is no bleed screw that I see on the injector pump for the 2qm15. Is it possible there is an air lock in the pump?

[Aaron]

Most likely cause below
https://www.hoyetractor.com/support/kno ... &suggest=1

[Le Blurr]

Thank you. I suspected it was something like that. Do you think forcing compressed air in the output side might free it up? I'm going to try the tapping while cranking first.

[Aaron]

I'm not sure about the compressed air. Might be worth a try. That spring is pretty tough though so if it can't push the plunger down I don't think compressed air would either but I might be wrong.

[Le Blurr]

I got it bled and it starts, but it will only run for a few seconds, and then dies. It fires right back up though, and does the same thing. If I give it throttle, it starts to rev up, but then dies. If I don't give it any throttle, it runs slightly longer, maybe 20 seconds, before it dies.

[winston]

Any chance you have trash in the tank partially blocking the outlet? If you take the line loose at the filter do you get a good flow of fuel.