clutch adjustment

How do you adjust the clutch on a 93 sentra? I don't think the clutch is hydralic since there is no clutch fluid resevoir. I know there is a little adjuster wheel at the end of the clutch cable connecting to the fork lever on the transmission. One way loosens the cable and the other way tightens it. The problem I am having is that no matter where i tighten or loosen it at, the clutch doesn't return. The fork lever returns to normal position just fine without the cable attached. The clutch pedal is going to the floor and staying. I can pull it up be hand as long as the cable is not to tight. What is it that makes the clutch return to normal position?