To narrow it down some, you may want to try some zero nic juice. My wife has this same problem and I searched and searched and searched for a juice she could vape, but everything made her cough. I tried PG, VG and mixes of PG/VG. At long last I found one juice she could vape... VapeRite Organic Waffle 18mg. She tried several other organic flavors and they also caused her to cough.
After some experimenting with zero nic, we found that she could vape PG and/or VG with no problems... it's the nic that seems to cause the issues. At this point, she's been able to vape just about anything I make that's 12mg. Anything over 12mg makes her cough. I still don't know why she can vape 18mg Organic Waffle.
I agree I'll just wait till I get of the plane that was the whole reason for quitting smoking so I don't have to be dependent on smoking. I vape because I like to I smoked because I had to.
Roscoe reacted to Brian in Coughing & Coughing