Purchased this off of one of my buddies because he has a mod now but I had it for a good week and it hit good with my last juice but now my new juice (max vg) I smoked maybe one tank and it was good and after i refilled it I hit it once or twice and its good then after all harsh burnt hits. If it's a wicking issue how do I go about that or if it's my coil how much does that cost? I don't have the tank on the whole picture of the pen anymore, this is my current one.