OC-6 diesel pump

[Michael30.06]

I removed the fuel lines between the injection pump and the injectors, to pull the injectors and oil the bores. As the operators manual says.
I though that would be my chance to put the injectors onto a poptester and see how they perform, but I dont have the right thread connection on my pop tester, so just oiled the bores and reassembled.
Now I am having a lot of trouble bleeding the pump.
Any tips you can suggest, I have already replaced the diesel lift pump with an electrical one, and I do have diesel flowing in the leak off or return line.