Old Audis use Hitachi ECUs to control ignition boost etc. functions. Below is pinout of MAC-11, used at least with MC1 engine.\n
1. Cold Start Valve 2. Ignition Module Ground 3. no connection 4. Hall Sender return ground 5. ground 6. ground 7. Tachometer 8. CIS Freq Valve 9. Ground 10. Coolant Sensor 11. RPM Sensor signal 12. TDC signal + 13. TDC signal - 14. no connection 15. Knock Sensor Positive 16. Knock Sensor ground/shield 17. Boost Gauge 18. Ground 19. Waste Gate solenoid control 20. Idle Switch 21. Fuel Pump relay ground control 22. Ignition Module control signal 23. Intake Air Temp sensor ground return 24. Intake Air Temp Sensor + 25. Hall Effect +12V supply 26. Full Throttle Switch 27. Hall Sensor signal 28. RPM/TDC shield wire 29. RPM return ground 30. O2 Sensor shield ground 31. Fault code light control 32. Brake Light Switch 33. O2 sensor output 34. no connection 35. +12 Voltage from ignition switch
For MSAVR most of stock wiring can be reused, but some extra wiring is required though.
See InputTrigger/AudiTrigger about RPM/TDC signal timings.
More information about installing MSAVR will follow once there is some more progress with project.