Usually, it's a wicking problem. Don't clog up the juice channels by jamming the wick into them, leave room for the juice to come up the channels into the chamber. Make sure you use the right amount of cotton through the coil...not tight and not loose, just fits into it slightly snug. Cover the air hole with your thumb and give it quick dry puff or two, then watch for an air bubble, that way you know it's feeding juice.
Edited to say, maybe I misread and you're a wicking expert! Is your voltage set right? They might have been pushing it with high power. I like my voltage set about 2.3 or 2.4 over the coil resistance. So for a 1.4 ohm coil, I'll start out at 3.7 volts and go up from there a little until I'm happy.