I just bled the clutch hydraulics! Whyy....
 

I installed a new slave cylinder and bled all the air out of the system. I then installed a BSS clutch hose from flyin miata, and re-bled. Clutch feels firm and nice. I start the car, let it warm up to operating temps, and the fucker won't go in gear. When I try 1st or Reverse, the car bogs a slight bit. I shut the car off, put it in reverse, crank, and the damn thing wants jump backwards. I had this problem before, so I changed the slave and hose. I assume the master cylinder is the last culprit, but I'd love it to be a cheaper fix. And that would save me the hassle of bleeding the damn thing again:bang:

Does it work if you pump the clutch pedal a few times before putting it in gear? If so, there's still air in the lines or a leak.

I had the same problem. I rebuilt both the slave and clutch master. Bled a couple of times - zero air coming out. It was just like yours when I tried to drive it. What I ended up finding is there was still air in the slave. Because it is past the bleed screw, it would never come out on it's own during a bleed. So, with the bleed drain hose still on, crack the bleed screw and push the plunger all the way back into the slave cylinder with your hand. I about guarantee you you get a bunch of air out. Tighten the screw and the spring will push the plunger back out, drawing in fluid. Should work like a champ then.

+1 air in the system, if you have to you can adjust the clutch petal under the dash so you have enough play to get it in/out of gears.

I just had the same problem you did, even used a might-vac vacuum bleeder to bleed the line and it still wouldn't hond pressure, ended up being a bad master cylinder, wish I would've known that before rebuilding the slave, then replacing the slave and spending all the time to bleed it. Just spend the $40 to order a master cylinder and replace, for the money it is better to know that you hydraulic system is good and all has been replaced, than have another failure and have to deal with bleeding the system all over again, just my 2 cents

Thanks for your help, i'm gonna try pushing the plunger and if nothing then will adjust the pedal, i'll post after.