What ECU ? If you are running a stock K-Jet system, they are mechanically operated from the metering head.
Sorry should of been more specific it's a mk2 digi 8v I just don't knkw where the injectors get there impulse to squrt from ?
ecu triggers the earth side of the injectors, from pin 12. the live feed is either from the ecu relay on pre-90, or fuel pump relay on 90spec (also from fuel relay on some later CE1 found in cabrio/scirocco)
