I have a 3g accord (carbureted) and occaisionally when shifting to neutral ie for stop lights its idle drops down to 100rpm (thats right, 100 not 1k) and wants to stall. This is an intermittent problem and so far I haven't noticed any exact conditions under which it likes to do this. What do you think has been causing this? Any suggestions would be helpful.

 

Check the pvc valve.