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...