My 1984 Z N/A has been running like crap lately, and before I went and spent any money, I went outside to see if there were any disconnected vacuum hoses, since the symptoms seemed to fit. Takes a long time to start, runs poorly at idle, needs to warm up for at least 5 mins else it will stall. I noticed a missing line, im not sure if it would be vacuum or not, im not much of a mechanic, so rather than try to describe it, i took pictures.
Any help is appreciated!

 

Welcome to ZDriver!

Download the FSM (Factory Service Manual) and check out where that vacuum port connects: http://www.xenonz31.com/reference.html