I just fixed a torch lighter for a friend.
1. dismantled the lighter and cleaned the nozzle where the gas comes out (held it gently with needle nose pliers and sanded it clean with a fine modeling file
2. tested it; it worked fine. put it back together and it didn't work again.
3. dismantled it again - it worked fine.

grrrr
4. noticed that when I put the metal cover over it the spark started arcing to the lighter body instead of the fuel nozzle. bent the wire a little closer to the nozzle. (I think I bent the wire a little while cleaning the nozzle.)
5. done
If you feel comfortable doing this and the lighter allows you, I recommend cleaning any built-up carbon from the fuel nozzle that may be interfering with spark. Also, look closely to see exactly where that spark is arcing to.
Just my
Also, if this voids a warranty maybe you shouldn't try it.
Good luck!