This weekend I'm about to swap out my clutch for a new exedy stage 1. Frequently I notice that when I'm driving down the highway about 70MPH, if I dip the clutch coming off an exit ramp, the rpm's won't drop. It's as if the gear doesn't disengage. It only happens maybe 30% of the time, but it's out of nowhere. This leads me to believe it could be a clutch pedal adjustment issue, or a master/slave issue. I have yet to change my clutch fluid, it's very black tho. Doing that when I swap the clutch along with the rear main, tranny fluid, oil, etc. I'm just stumped on what to diagnose, cause I'm also having idle problems. Probably just a dirty IACV though, I'm also gonna check on that later. But any clues on to what the problems are leading to the clutch not fully disengaging occasionally while dumping it in gear?

 

Just change out the clutch first.