95 SC2 5 speed manual transmission
Occasionally, when at idle and with the gear in 1st and the clutch pedal fully pressed, it feels as if the clutch is slipping and the gear is trying to engage.
The car starts jerking/jumping (but doesn't move). If I release the clutch a little and the gear starts to engage a little the jerking stops (but the cars starts inching forward as the gear is somewhat engaged). The problem is much worse if I have the car in 1st gear when I start the car. I start the car in neutral with no problem.
Is this air in the line, a faulty slave cylinder, master cylinder? It seems to me that it is likely something wrong somewhere within the clutch system.

Any help on what is wrong and how to fix it would be appreciated.

 

Just a shot in the dark, but have you ever changed the clutch fluid? If the stuff (brake fluid) has been in the car since 1995 it has no doubt picked up a bunch of moisture. Change it bleed it completely and see if the problem goes away.

 

No, I haven't replaced the fluid. I am doing that now. I noticed you can't bleed the system and RichPin's video indicates to replace the reservoir fluid. I will do that, replace the reservoir fluid, drive for a while, then replace reservoir fluid again. By repeating this process several times hopefully it will purge out the old fluid in time.
I tested the brake travel distance - pedal goes a little over 6" as it is supposed to and the 'clutch fork travel' distance is about 0.55". This is a little more then the 0.44" that they suggest but that could easily be a measurement error. It's definitely not less the 0.44".
This is actually an intermittent problem when running and only usually happens only when sitting at a light for an extended period. It almost always happens though if I start the car while in gear (with clutch fully depressed). Now I always just take the car out of gear when coming to a light and when I start it.

 

I would think you are in the right area with a faulty master or slave cylinder, inspect area for leaks. At the transmission for the slave, possibly inside the car under the rung where the master could be leaking back along the plunger and then through the firewall. Generally I have seen slave cylinders cause problems, once in a while both or a master.

 

Well, I replaced the transmission fluid and changed the transmission mount and now the car is behaving much better, and it sounds a little quieter.
Haven't had the car shake - which is why I thought the gear engaged when the pedal was fully depressed, yet.
Hopefully all is well.

 

Hope thats all it was brother ............ keep those fingers crossed.