Not exactly sure what you mean by "an acid type feeling", but I am assuming you mean irritation and/or dryness. This could be from PG (propylene glycol) in the juice. This does happen to me quite strongly, and many others here. Many here find that juices with higher VG (vegetable glycerin) content, and lower PG content, dries them out far less than juices that only use PG as the vehicle. In fact, I make my own VG-only juices, and have almost no dryness issues at all. I also assuming you are vaping with a "regular" PV, like a 510 or kr808D-1, and not with a high voltage PV. High voltage with normal atomizers or cartomizers can produce very hot vapor, that can also have irritation effects.
You might post this to the Health and Safety subforum if you need more discussion to communicate more details of your problem:
Health, Safety and E-Smoking
Realize however, that we are in general not doctors, and cannot give medical advise, but it seems like your problem is a pretty common one, if I am reading it right.
