Jerking to heavy of weight up and using all of your arm. Use a controlled motion to really contract your back. Try a looser grip on those exercises. I found that I take SOME of my arms out of the lift when I do. However, once you get to heavy weight it's hard to have a loose grip.
For DB rows imagine pulling with your elbow and bring the weight to you hip. I bet when you BB row you have a overhand grip hence not having as much pump in your bis? How many pull ups can you do? If you can do strict pull ups and not flail like a retard trying to swim your arms won't be used as much if you flail.
I personally completely disagree with fuzzyapple, jerking the weight IMO does not at all use your arms more, but rather brings other muscle groups that shouldnt be used into play (your hips for example) I also completely disagree that loosening your grip is a good idea, all that will result is a lesser force transfer and you wont be able to move as much weight. When I do pullups, I ONLY ever get a pump in my arms, and my lats are rarely sore the next day, however my weights are going up, my back is certainly getting bigger. I recommend you pay more attention to progression of weights and reps. Once you have added 100 lbs to your BB rows, and are able to do many weighted chinups, I promise you will have big and powerful upper back muscles, regardless of how much you "feel" them working during an exercise.
Yes that really is all there is to it. Overhand grip lowers the biceps contraction when compared to a overhand grip. Give it a try, next back workout use a underhand grip and your bis will be used more.
If your not already you are doing chin-ups, which would use your bis a little more than an over hand grip. If your trying to work your back more use overhand grip.
The back is notorious for not being able to feel the muscles being used. Concentrate on contracting the muscles being used and use perfect form until you get the hang of it and have a better mind-muscle connection.
for vertical pulling find a dual pulley lat machine and learn to feel your lats on it with a moderate weight range and once you get your form down dumbbell rows you will start to feel your back in pull ups, i would do neutral or overhand grip.