Power Issues/Seems to be related to ESP/ABS -- Audi s4

[Richard L]

Do not start the system until the kety switch is on the pre-crank position. If the system is switched on (battery power), the system will spray fully will flood your engine.

This is becuase if there is no 12V power to the fuel injector, the system will mistakenly think the injector is at 100% duty cycle and start o inejct.
Only manually start the system after the enigne is running.

When the system was powered from the battery, did you still have flickering problems?