i dont know a hell of alot about engines so maybe someone a bit more in the know can shed some light on this.
(Astra Mk2 1991 1.6)
this is a totally a intermittant problem one day it is fine the next it is coughing and spluttering and the revs are soring but the car is slowing down.
totally flooring it it gives a few jolts and picks up again but as soon as you even slightly bring your foot up the same problem occurs.
it gets to the point where you have to keep changing down the gears to stop from stalling.
all this makes maintaining a steady speed a nightmare and it wont idle properly, but you leave it for awhile say 30min and it goes perfect.
well it unfreezes likeyou said when you stop the car and let it rest for a bit. This isnt a fix i know. Allot of people have this prob, usually remedied by making the inlet air warmer. The standard air box has a pipe that hovers over the exhuast manifold, and some hot air is drawn from there to stop carb icing. Carb icing is usually a problem with cars running aftermarket air filters like k+n where the air flow increases and its not drawn from above the exhaust. whats your setup ?