Overtightening tends to compress the older white insulators, blocking airflow. I've done some tinkering, and fixed mine so it works great.
1) i drilled the three airholes in the base out one size, 1/16" i think. tiniest drill bit you have.
2) ream the center of the base with a 5/16" bit. Just enough to remove the burs from the first step.
3) Place your coil head in a pair of vice grips and LIGHTLY compress down the length. The insulator may "smoosh" out a bit. use a nail clipper to trim off the material to be flush with the head while compressed.
4) reassemble and test. Should work MUCH better.
Finally, if this has loosened it up too much, use a $4 airflow controller to fine tune your draw. i have found that the draw does tend to tighten up with extended use of a coil, gunk building up on the flavor wicks and coil I think.