My 77 280z is running rough due to this vacuum leak I’ve tried searching images to where this hose goes to but can not find anything about it also it’s running really rich and would like to get some help on what I should be looking at to fix that problem.
Looks like you have A/C on the car thats been disabled? You have a cracked/leaking vac hose to your FCID, but that would only matter if its hooked directly to manifold source and bypassed the megnet valves.
You may want to trace all the vacuum lines that should go to the A/C control system to ensure you don't have anything open. The FSM lays out the whole system and how it operates together. If you remove the A/C components you still need vacuum to operate the heater bypass doors.