You might have a broken pedal assembly. I had that problem and had to have Jerry weld it.
RRE's Clutch And Flywheel Tech Info
If you can wiggle the pedal with one hand, and you don't feel the clutch master cylinder rod moving with the other hand, you are suffering from this problem. The solution is to replace the pedal assembly, or possibly weld the linkage where it is loose. Either one requires more work to remove and reinstall the pedal assembly, you don't even want to know how much hassle it is.
Its almost all the way down the page under clutch adjustments for a 1G.