Content missing from my site feed
If you're seeing only partial posts in your site feed, then you most likely have it set to include only excerpts of your posts. You can change your site feed settings from the "short" to "full" content option to fix this.
If entire posts are missing from your site feed, there are a few other things you can check on:
Are you viewing your feed in a browser?
If so, clear your browser's cache and then reload the feed, to make sure you're seeing the most recent version.
Are you viewing the feed in a feed reader?
If so, your software may simply have not checked for updates recently. Desktop applications may have options to customize how often they check for updates, or you may be able to click a "Refresh" or similar button to force an update. Web-based software may be more likely to have its own update schedule, which means you might have to be patient until it picks up your new posts. You can always check your feed in a browser to see if the new post is actually there, which will tell you if the issue is with your feed reader or not.
Does the post appear in your blog?
Make sure the post was indeed published correctly, and not accidentally saved as a draft.
Does your feed validate?
Try entering your feed URL into FeedValidator.org to see if there are any problems with it.
Is the post a recent one?
Blogger feeds show the 25 most recent items (posts or comments) available. Older posts will not be included, regardless of whether they appear on the front page of your blog or not.