strange problem with 1985 manual 80,000 miles.
surging idle,
 throttle body tight and returns to stop every time. switch ok and working.
all idle booster and cold start valves have the vacuum blocked at the manifold<makes no
difference>.
vacuum advance seems tight and no leaks.
car will surge at random to cutoff and continue to do so untill the throttle is blipped a random number of times, then it is ok for a while. any ideas?  runs great otherwise.
thanks
mike