What sort of vaporizer is it? I dont think that vaporization could cause you to have these symptoms, esp not if youre coming from smoking. Maybe if its not a quality vape thats made of some sort of hazardous material or something, but its likely you would have smelled tasted it by now if it was bad enough to cause this.
I think a doctor once told me that, after you quit smoking, things will get worse before they get better, as far as coughing stuff up. It's just your lungs trying to work out all that gunk (for lack of a better term) that has accumulated in them over your period of smoking.
A lot of ppl who have recently switched to vaping only have started threads here asking similar questions. They all basically are worried that its not going to improve at all because they havent noticed an improvement after a couple weeks. Give it a few months, it takes time.
... although if the stuff you're coughing up is actually BLACK, then you might want to show or at least call up your doctor. What i coughed up during and shortly after the time when i was smoking was more brownish/green. Black could indicate something more serious than just the normal smokers lung recovery symptoms, like coagulated blood or something. Could be nothing serious, but its best to err on the side of caution, yeah?