Hi... in my opinion, probably the atomizer is not getting a proper juice flow.....you may try taking a couple of short drags from the tip, without pressing the button...this will circulate the juice better , before you actually press button to take a drag..
Secondly, check the inside of the pointed metallic nozzle of your atomizer, there should be a wick sitting there , pretty close to the mouth of that nozzle, adjust it if it has fallen inside...
Thirdly,if the above don't solve ur issue, then i believe it's the juice some juices just vaporize faster (especially the clearer ones) without giving enough time for wicking... IMO 1.7 ohms is pretty low, if you want to stick to your tank systems or any particular juice, try out the 2.2-2.4 ohms range attys.
I was having a similar problem with my menthol...which seemed to lose all flavor on a 1.7 ohm...even a 2.2 fell short for it..i dont blame the system....i was lucky enough to have my 510D boge cartos to fall back upon. it gave me much better menthol flavor on the twist at 3.2v...not only that the twist made my cartos taste better than on a normal 510 battery...producing much better and consistent vape....so I would also go with others above, who have recommended on the cartos....