Car won't shift while driving

[firestorm66]

Hi guys,

I had something happen to me while driving that I've never experienced before, I came into town last night and suddenly I wasn't able to shift the car into gear. If I stopped the car and pushed in the clutch while in first gear she would just die, I had to keep the transmission in neutral. The clutch pedal was firm, not squishy or anything like that. This morning I looked things over and didn't see any hydraulic fluid missing from the master cylinder. After searching the internet it sounds like it might be the slave cylinder. The strange thing is that I was able to put my car in gear this morning and drive around a bit. Is this common when a slave cylinder is on it's way out for it to periodically stop working?

[DCaff300ZX]

OK, I think maybe I know what's up from a similar experience in a Stanza.
My brother's Stanza suddenly did what you said and then eventually wouldn't disengage at all so he checked the fluid and its not full but enough, and so after some research checks for and finds air in the line. Fills it up and we bleed it, but it's back again in a week or two and after another fill/bleed, is empty next time and we find a cracked line that finally failed.
You may be in stage 1 with your issue, the Stanza has a very similar layout and early on would do just as you say and after failing first time, then would allow one more go the next day to move it before the air heated enough from compression or more fluid escaped to cause the failure of engagement.
Moving to your Z realize there are also two bleed points on the Z32 to complicate things and add a place to check, I'd look to drain and refill then (or, at least) bleed the system, checking the hardlines of course as well and also that slave- cheap enough to just replace while there doing the rest if you're pretty sure it's the old worn stock slave.
Hope this helps!