my old 85 Accord LX had all sorts of carb problems, including where the engine would rev up to almost 5k before i shut it off. a carb rebuild did the trick and some of the vacuum lines were shot too. double check and then redouble check the vacuum lines. even one that looks good may be cracked or not seated right, causing erratic operation (but you already knew that). The vacuum lines are what kept the car good with the emission standards of 1984/85 and one bad line can throw the whole thing off.