If your website isn’t receiving hits every minute the import process won’t work every minute. This is one of the reasons for implementing the server cron.
On the other hand, you could use a website monitor service ( ie: http://www.internetseer.com/services/index.xtp ) that will access your website every hour or so. You might want to try this, it’s not the ideal frequency but at least it will be consistent.
More such services can be found here: http://www.hongkiat.com/blog/monitor-website-up-downtime-30-free-web-services-and-tools/