Hey Pbalias,
Check out:
http://67-72chevytrucks.com/board/Ultimate.cgi?action=intro&BypassCookie=true
I'm more interested in the older trucks, but they might be helpful.
As for the problem you are having, that sure is a wierd one. Most modern car troubleshooting starts with a code reader to see what computer codes are being thrown by the 'puter.
Sholin