So you removed it.........why? This actuator directly controls the pressure going to the fuel injectors. I am more familiar with the K system, than the KE.........I will tackle this in the near future.

Since your car ran fine before, and now not.........after you removed this item.........I would guess it is not installed poperly. I have a car with KE-Jetronic, and the actuator screws are sealed in some epoxy........so I don't take it off. I would remove it, and re-install it, to see if that helps...........look very closely, to see if some part of the FD goes over, or under, a part in the actuator. Or, maybe you left a part out???????????

I don't know why the car runs with the plug out..........maybe it is bypassing the actuator, thus giving full system fuel pressure to the injectors.