I have a 1996 Jeep Cherokee with a 4.) liter engine and a 5speed manual transmission. It has 168,000 miles on it. Recently, while sitting at idle it sometimes is impossible to put the car into gear, even with the clutch pedal fully engaged. Once the car is moving it is fine. Under hard acceleration there is no obvious clutch slippage. The problem is getting more frequent. I checked the fluid level and it is full. I am guessing, hoping and praying that this is just a bad master/slave cylinder. Any thoughts out there?
It does sound like a clutch master cylinder problem. The next time this happens cycle the clutch pedal out and in and see if you can get into gear. Also, pay attention to the pick up point of the clutch pedal (the pedal location where the clutch just starts to engage). If that goes lower to the floor when you have a problem, suspect the CMC. However, you could also have a problem with clutch disc runout or a pressure plate problem.
Good luck. Let us know what the outcome is.