Below is a clickable image map showing the main components visible under the bonnet of an XS TU3S engine:

I hope to
add a clickable image map of the XY8 (twin carb) 205 XS engine to this page
soon, as well as one for the later 1360cc Bosch monotronic injection XS found
in XSs manufactured for other countries.
Below is a scanned picture of the XY8 engine. It is copyright
Halfords (sorry!). Cheers for the pic Steve!