You can use Google’s Webmaster Tools (Google account required) to help pinpoint the issue:
It could be you have a robots.txt file that is blocking, or it could be an issue in your .htaccess file, or it could be that your hosting company is blocking Googlebot in their access router.
This link will help you further diagnose the issue:
If you are still having issues after checking all of that then PM me and I’ll try to help you further.
