Cummins 5.9 stalled and wont start. Injector pump?

I hope it is just plugged filters. We had a loss of power recently going up hill or when pushing the throttle down hard. Changed out the two fuel filters, one on engine and one bigger one in the back and all was well again after system was bled. I have a 5.9 Cummins / Allison trans as well. Good luck