I would simply look at the Hoses. If it looks like they have been there a long time I would change them.
The Fuel Injection Hose sold at the regular Auto Parts places is around $3 per foot and is liked with a what members have said is Viton.
There is a thread on that somewhere. Below if the GoodYear site and it tells you what you can run through the hose.
Fuel Injection Hose SAE J30R9 or 30R90
http://www.goodyearep.com/BuLandingPage.aspx?id=17700&terms=fuel+injection+hose