You are correct, there are sensors for the cams. I was wondering if they need to be cleaned, someone else in a different thread on this forum had them "de-glazed" along with whatever part the sensors sense, which fixed their problem. Dunno if codes are generated or not.

For 500E information, there are some websites out there, or you could try to find one of the factory "Intro" manuals like this one:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7909290576


PS: I want to turn up the 603 fuel just a hair, maybe 1/4 turn on the full load screw, and see what that does... don't want to go any further without intercooling though! :p