Hi guys! First post here.
I got my 1979 280zx a while ago, and have been giving it the maintenance it deserves. I fixed a lot of stuff that was wrong with her already, and the only thing that I have left to figure out how to fix is this:

When I decelerate quickly, the motor has a hard time holding the idle. Let's say you have it in neutral and want to rev it to impress your friends. The revs go way below 1000 when you let off the gas, and sometimes the motor stops. It has a hard time going back to idle. Reading for a while, and inspecting around the engine bay, I found a vacuum port without anything attached to it, just below the throttle body. I think this has to go to the canister (the canister was missing the vacuum line as well) and it's the boost controlled deceleration device vacuum port. The canister also has another port, that goes to the distributor, but I didn't find any vacuum ports on my distributor to connect it there. So, do you guys think is there a way to make it work without these vacuum lines? Should I get a new distributor with this vacuum port on it? I already connected the throttle body port where it should be, according to the canister (it has a sticker that says so), but I have another port without anything attached to it, and the canister says it has to go to the distributor. Thoughts? Any help is appreciated a lot!

 

I also own a '79. I will check on the vacuum hose flow and get back to you

 

Thank you very much!

 

Welcome to ZDriver!

The FSM has many helpful vacuum diagrams: XenonZcar.com S130 Factory Service manuals