You are getting dry hits, or partial dry hits.
If you're using CE5's that have wicks in them that you can see then you need to keep them wet. You don't need to leave it alone for an hour to soak in, you do need to tilt the device every other drag or so to keep the wicks nice and wet.
Probably the easiest best cheap clearomiser available right now is an Aspire head CE5 which you can find online at lots of vendors for about a fiver. You can also get a bunch of other bottom coiled clearomisers that won't need tilting like this the cheapest and most reliable is the EVOD.
The CE5 you have already should work just fine provided you keep the wicks saturated with juice often.
Another problem that can happen is after a while the head gets gunked up with burnt on juice and then you'll only get dry nasty hits from it as little to no e-liquid is getting to the part that gets hot. If oyu've often been getting dry bad hits then the gunking up can happen a lot faster than it would normally.
There is a coil inside every atomiser that gets hot and turns the liquid into vapour. The coils typically get a lot hotter than this vapourising happens at, though this is balanced out by the liquid cooling the coil a little. If not enough liquid gets to the coil then it gets too hot and burns. Over time the more juice that burns onto it the worse and worse the quality of vape gets.
On any top coil atomiser (where the coils are at the top of the tank and wick dangles into the liquid) like a normal CE5 fill it up and tilt it to get the wicks wet, wait a minute or so and then vape. Every other drag you take give the thing a tilt again to keep the wick wet and you should get the best performance out of it. Evods and Aspire clearos don't have this tilting requirement, and there are hundreds of makes of CE5's out there and some wick much better than others, but all of them benefit greatly from a frequent tilt between vapes.
If you are using a fixed voltage eGo then don't worry but if you can change the power from the battery you're using then keep it set to a little bit under 4volts at most and it should be fine.