What battery device were you using before the Vamo?
The Vamo uses a cheap
33.3 hz PWM (pulse width modulation) chip commonly referred to as the
"rattlesnake effect". In fact, most of the Chinese-made mods use this chip. Some people find this lower frequency to cause a harsher or hotter vape requiring a drop in voltage/wattage, especially if you prefer a cooler vape.
The iTaste VV3 & MVP, Provari, and the DNA mods use a
much higher PWM (800 hz or thereabouts) PWM chip which will show up as a flat line on an oscelloscope, and
better filtering methods. PBusardo shows this in his reviews of mods when comparing the different mods. Not everyone notices the difference in PWM, many do; some may even prefer the 33.3 hz chip. I prefer the higher PWM of the Provari and MVP. This allows for a cooler, smoother vape, IMHO.
http://www.e-cigarette-forum.com/fo...itaste-mvp-dont-vape-same-provari-dna20d.html
http://www.e-cigarette-forum.com/forum/provari/381232-provari-oscope-vs-vamo.html
You are using the correct resistance cartomizer; nothing to change there. You are priming your cartos the same as before. The only change in your vape routine is the Vamo itself and there likely lies the problem.