1989 Pao Connector Next to ECM, disconnected?

Hello everyone,

I have an issue with the carburetor where it doesn't fire the second barrel jet when accelerating. I realized this by connecting the diaphragm for the second barrel and immediately the jet started firing. Since this second jet is not firing, the car bogs down and doesn't accelerate of completely dies.

I also noticed there is a connector right next to the ECM that is disconnected and wondering if that's what's causing the solenoid valve from opening and not creating a vacuum for the second barrel diaphragm and not activating the jet. I'm not sure if I should connect it, or if it's disconnected for a reason. I've never been able to solve this issue.

Any ideas?