Generally speaking, drawing attention to a question is what bounties are for. However, because Puzzling.SE works differently to most other StackExchange sites in that the OP generally already knows the answer, there's another way in which you can bump your question:
Add a hint!
Not only will this bump your question, it will also (hopefully) make it slightly easier for people to finally find the right answer. Generally, hints on Puzzling.SE are hidden in spoiler tags, so that if someone wants to try and solve the puzzle without that help, they're perfectly free to do so, and can then use the hint(s) to help gauge whether their solution is correct or not.
It's considered bad form to add hints or bounties too early - wait at least 24 hours, to give people from different time zones a chance to see the question - but after that, you're perfectly welcome to bump a question regardless of how much time has passed, so long as you don't do it too frequently.
(As a final note, if your question has at least one answer but no accepted answer, the Community bot will occasionally bump it to the front page so the answers can be "reviewed". I don't know how often this occurs here on Puzzling.SE, but I've seen it quite frequently on Movies.SE.)