First off, big thanks to mkrad and nigel for the wiring pictures, diagrams, and such! You guys helped me out a lot.
However, my '90 Corrado harness has a black/white wire on pin 23 of the ECU harness. Nigel's pic doesn't show it, and mkrad's pin-out sheet says it is "Not Used", and it isn't on the accompanying ECU diagram. The Bentley says it goes to something called a Digifant Control Relay. What does this do? Do I need it?
Oh, and mkrad, a couple other data points for your pin-out sheet. First, my harness also has a green wire coming from pin 16, which you also say isn't used on your sheet. A little digging in the bentley says it's the AC wire, and I noticed it is mentioned on the wiring diagram you have on that page. Second, my fuel pump relay wire (pin #3) is red/yellow. Your pin-out sheet says it should be red/green or yellow/blue, but the diagram shows it as yellow/blue or red/yellow. Maybe a typo, or perhaps three different possibilities?