Clutch pedal

Doug2009Z

I've been noticing that randomly after driving my Z, I'll get in to drive and the clutch pedal has no pressure the top half of pushing it in. At the half to three quarter mark of pushing it in, I start to feel the normal pressure. This usually happens after I've driven through a lot of stop and go traffic. The car is driveable when this happens. The clutch just engages closer to the floor than normal. It returns to normal after about 2-3 minutes of driving. I'm not really driving hard. Sometimes when I drive it harder, this is not an issue. I've checked the fluid level and it's normal. Anybody have any input? Everything is stock. I have the Z1 csc elimination kit and road racing clutch bought, but not installed yet