Check out this site:
911 CIS Primer - Fuel Hoses
I posted a link to this site in a thread a couple of days ago:
http://forums.pelicanparts.com/911-engine-rebuilding-forum/765769-excellent-cis-information-troubleshooting-resource.html
Jim has put together an incredible resource for CIS troubleshooting--there are diagrams, component descriptions, etc. Enough info to help you solve all of your CIS woes.
Here is one of the many diagrams from the site:
There are accompanying descriptions and legends for each diagram.
Hope this helps you out
Cheers,
Alex