Honda Repair: Idle goes up and down, coolant leaks, honda accord

Question
hi i have a 92 honda accord lx 5 speed manual i have two problems
1. all my gears work except 3rd and it used to catch but then one day it just stop it used to grind even when you would but the clutch in and now it don't work at all is it my clutch or transmission?
2. when im in netural it idles up and down when i let the clutch out a little bit it will stop idle like that what can that be i cleaned my fuel injection and there is no vaccum leak either what can it be?
Thank you
Nathan  

Answer
Hi Nathan, This could be several things, but lets try and take the least cost worthy route first. If your clutch is grinding like that it probably needs replaced, however if your other gears are working first check to see if it can be adjusted, if not a new clutch will cost anywhere from$1200- $1500 brand new. Now for the idling up and down,first check to see if you have any coolant leaks,if so its probably your thermostat going bad,if this is not the case then it could be your distributor. let me know the outcome