Ignition problems

[Christo Atanasov]

After I bought my Audi 200, I saw that it has problems with ignition control. It is KG engine with Mac-05A ECU. But exowner for some reason changed ignition coil with a regular coil without ignition trigger Transistor (Ignition booster) attached to a regulat TCI Ignition switch, so I have no advance correction.
I found another 2-nd hand coil with defective trigger, bought a 20A transistor and conect it. But no efect.
Also speedo and tacho doesn't work. So I think it might be defective TDC ot RPM sensor, checked with LED, and it blinks when I crank engine.
Another think I saw - When I drive with this extra ignition system connected, for some reason my ECU goes in self diagnostic mode, and tacho needle changed between 3K, 4K, 6K when I step on the brakes.
Where might be the problem - defective ECU?
How often this hitachi unit defect?
Might be another reason?

Regards to all,
Christo Atanasov
'85 Audi 200 Ti - KG Engine code