One thing I have started doing when a tank is hard to draw on, because of thicker liquid, or whatever (I'm new too), is to remove the tiny piece of plastic with it's one hole. Once you do that, there is a second even smaller piece inside the mouth piece. Those I throw out. When the liquid is hotter/thinner I just put back the piece with the hole and it's little prongs at the ends. This has made the tank a little more adaptable for me.
With my tornado I now get up a tank set-up and another boge cartomizer set-up. When I'm craving, I suck the hell out of the carto, I chill out with the tank to get my "suckle" time in.
I wonder if your battery and/or atty's not working right? Can you get replacements? Also, I love the heat of the low resistance cartomizer that I've started using- it turns my ego/tornado into a high voltage animal! I use a plastic drip tip to protect my lips from the heat. The vapor is really thick and white that way, too.
Hope that helps. TG