Are we talking old style Kanger coils (or the subtank style), it could be that the juice is either too thick or even too sweet for the coils.I have a drawer full of Logic cartridges maybe that is what you were thinking.
On another matter, my Kanger and clone dual coils don't seem to be lasting very long with Caramel Deluxe from L&T. Could it be the liquid or just duff coils, getting a few days out of them at present. Trying the clone coils again.