okay, after my recent queries, i got back to the car and i tried the paperclip trick (again).
The car is a 2.0 8v 1993 (or late 92) Astra CD.
I've tried to find a stamp on the engine so i know what i have, but i can't find anything.
The ALDL connector is this:
I shorted pins A&B, got 12, 12, 12 (as normal) and then i got 71, 71, 71 and then 12, 12, 12, and then 31, 31, 31.. then 12, 12, 12, again and back to 71, 71, 71.
So by reading that website (topbuzz) it would suggest i have GM Multec CFi ignition. But again, according to that website, the 2.0 should have Bosch Motronic 1.5.
What makes it more confusing is that GM Multec does not register a fault code 31... only the Bosch Motronic does!
So if we assume that i read the contents of the Bosch Motronic Code Chart:
31 - Engine RPM signal (crankshaft sensor) - No signal
71 - Air Temperature Sensor (ATS) - High voltage
Where are these located and how can they be tested/fixed?