You know that Lucas ECU that nobody has circuit diagrams for? I do... but you'll need to have AutoCAD to open them.
The ECU is built on two circuit boards that are linked by wires. Care should be taken when dismantling.Main PCB diagram: Here
Second PCB diagram: Here
Update: Since I drew these circuits I have received an alternative set of drawings from another source. These show three or four minor errors that I made when drawing and re-drawing the sketches I made, to arrive at the CAD versions. You are still welcome to download them but be aware that if you are trying to fault-find to the last component, you may encounter some results that appear incorrect but probably aren't! Allow me to correct my cock-ups and I'll post the revised drawings ASAP... sorry about that!
Just a reminder that the Lucas circuitry is of course copyright and probably patented too, so I couldn't possibly condone you copying it, should you feel the need...