I have always had trouble feeling the pump in my back. Today, I tried this workout I got from MD, Markus Ruhl reccomended it.
T-bar rows 4 sets
DB rows on incline bench face down 4 sets
Pull downs 4 sets
Cable rows 3 sets
DB shrugs 4 sets
I did 10-12 reps on everything. If you need a new back workout, I suggets you give this one a try.