you definetly have back pumps. i only get them when i'm on a methylized orals. i used to get them alot from prohormones. i've also gotten them from d bol. like was said earlier, alot of water and 3-6 grams of taurine a day will keep them away.
I remember getting them really bad after doing dead lifts.
i don't understand how you are getting them if you are only on injectables.