Sorry for the many posts in this thread, I'm just trying to document my experience and symptoms in case it can help someone down the line...

So this morning I said, "eff it!" and decided to drive the Z to work. Although the clutch pedal was returning to the top of its travel after sitting yesterday evening, as soon as I backed the Z off the ramps and went to head out of the driveway the clutch was again resting at the lower point (below the point where the return assist spring would take effect to spring the pedal back to the top of its travel).

But, the clutch was engaging and dis-engaging correctly, so I kept going. About 1/2-way through my drive traffic slows down to a stop-and-go. It was after a couple minutes of clutch work and shifting in this that the pedal began to return all the way to the top of its travel. It got progressively easier for the pedal to return all the way back up, and a few minutes of shifting later the clutch pedal was behaving normally. The dis-engagement point is still very low in the pedal travel (only an inch or so from the floor), but the pedal did firm up and work fine for the rest of the drive. We'll see how things are behaving on the drive home this afternoon.

So a few things come to mind:
1) The only thing I can think is that there is still air trapped in the system somewhere, and it becomes less noticeable the more the clutch pedal is used
2) I will be upgrading to the RJM Rev.4 pedal and a Tilton or Wilwood CMC at some point - I would like the clutch dis-engagement point to be higher in the pedal travel. Also, the design of the RJM pedal looks like it will provide a consistent spring return force, vs. the "hitch" in the OEM pedal travel. But for now, I'll probably finish out the season with the clutch hydraulics as they are if everything performs the same on the drive home tonight, and I'll look to upgrade the system over Winter.
3) It's good to be driving the Z again

FYI, my Z is at just a tick under 128k miles, now.

 

When bleeding, I compress the slave by hand with the bleed port open. It's the only way t get all the air out

 

Do you do that with the clutch pedal depressed, too? Or just compressing the slave cylinder on its own?

I know I did compress the slave cylinder with the port open once or twice while I was down there, but I can't recall if it was while I had my daughter pressing in the clutch pedal or not.

 

Pedal depressed, bleed valve open and then compress the slave and close the valve. Do that a few times and let it sit.

Then have someone watch the master for air, and compress the slave and see if you push air up and out of the master. I do that a few times, and usually push air out every time

 

Just a quick update: I've been driving the Z for my commute and the clutch pedal feel is still good - definitely is at least back to the same feel as before the problem.

I will likely bleed the clutch again over the winter, just to make sure there is no hidden or trapped air bubbles.

 

This entire post has helped me a lot, I have the same problem with my Z but it’s been sitting for 3-4 months now bc I can’t work on the car without a lift. The same exact things have happened to me and I figured it’s the clutch having air bubbles in the line. I’ll try that new method of bleeding and keep you updated if it works. Thanks for documenting this entire process

 

I was just going through this issue after a slave cylinder change. After bleeding the clutch I could only get a small amount of travel in the pedal. What worked for me was wedging a piece of wood between the seat and the clutch pedal holding the clutch pedal to the floor. Leave the cap to the clutch fluid reservoir loose and let it sit over night. From what I understand the pressure in the system will force the air out. The next morning I put the cap on, pumped the clutch pedal a few times, and I had a normal clutch again. I also remember being told it is important to bleed the clutch again after doing this so I just gravity bled it until I had put a bottle of brake fluid through the system. I did this during the process of swapping my blown motor and getting a clutch pedal back was the most frustrating part of the swap.