So when mine did this, i had the clutch installed backwards. I would double check the way the clutch disk is installed. I even bought a damn Wilwood master Cylinder kit and a new Slave talk about wasting money....

 

I have the clutch pedal adjusted correctly now. I left it sitting over night and earlier today I had a strong clutch pedal however it is still not coming all the way to the top as fast as it should. The pedal can not catch my foot when I release it.

 

I was having the pedal issue before the new clutch kit..