Questions that you have personally favorited should be more visible in search results. I would recommend an implementation like Google Starred Search where favorited results can appear in a single line format up at the top.
Maybe it is just me, but don't the Search function and the Favorites system kinda serve opposing goals? Search is used to obtain the location of information that you do not have. Favorites mark the location of information that you have already found so you can easily find it again. So, if your Searches prioritized your own Favorites to the top... your search would turn up information you already have!
Or maybe you're a person who favorited a question because you had the same question and you wanted to wait for an answer. Favoriting gives you a nice way to get back to the question when someone does decide to answer it. If you have already found the question in order to mark it a favorite, then why would you be trying to find it again through a search?