Hi all, new poster here, although I'm not totally new to PVs (using them for around a year now). I experienced similar issues with the Joye eGo and eGo-T, and have finally (FINALLY) retired them. However, the issue (as others have mentioned) could be your e-liquid. Are you using only one brand, which might need to put some work into their quality control? Is the bottle of liquid that you've been using as a control nearly empty or old, has it been kept in the sun, heat, etc.? All valid considerations. In my case though, the problem stemmed mainly from the design and build quality of the PV itself. Mass-produced Chinese PVs seem to be very hit-and-miss, judging from the totally dissimilar experiences their users report. I can tell you with certainty that the manufacturing tolerances of these devices occupy a very broad range. For example, after a particularly frustrating ordeal involving a box of brand new eGo-T attys and their inability to perform in both a satisfactory and consistent manner, I threw a little tantrum and played mad scientist to find out why I couldn't get my PV to perform similarly to any previous day. It turned out that wick size and positioning was totally different among every one of the attys, among other things. Moral of the story: these devices are not made with precision or durability in mind. I recently purchased a nicer mod, and have so far been pleased with it--it performs better than the eGo ever did. I suggest you continue experimenting, and if your efforts are unsuccessful, consider an upgrade.