Mozilla does not operate its own search engine. Instead, Firefox is initially set up to search using Google. Is the problem in Google results, or a different search engine?

If you check Google in Internet Explorer, do you get different results than you get in Firefox?

Google

Google has a forum for questions about why sites rank differently than you expect or why pages might not be indexed properly. This is a companion to the Webmaster Tools. To explore those:

• https://productforums.google.com/forum/#!categories/webmasters/crawling-indexing--ranking
• https://www.google.com/webmasters/tools/

Other

You usually can switch your search engine back to Google by clicking the icon at the left end of the search box and changing it back to the blue g.

Try to disable IPv6 (check for other possible causes as well).

• http://kb.mozillazine.org/Error_loading_websites

For all readers, it is always best to post with Firefox if you possibly can with Help>Troubleshooting information. Helpers are often working in the dark otherwise.