1983 280zx clutch problem

My clutch was working fine. I went out to the car one day and the clutch pedal was on the floor and would not stay up when I pulled it back up. I checked the return springs and changed the clutch master cylinder but none helped. It remains collapsed to the floor. I would appreciate any help!

check your fluid in your clutch cylinder.. you also might need to bleed your clutch lines as well.. and if it still wont work then replace both slave and master cylinders and clean out your hydrolic lines...