What flavor are you vaping? Also, what's the PG/VG ratio? Like @Walt said, the bad taste could also be coming from the fact that you have a bad cold, have vaper's tongue, and bad taste buds. Make sure you're drinking lots of water (not soda/pop, coffee, tea or juice -- just water). Vaping dehydrates you and the "vaper's tongue" you mentioned is basically dehydration.