The Boeing 727-100 also operated to San Juan and Mexico City.
The A310 were introduced in 1995 and flown originally to :
New York JFK: A special fuel tank was incorporated in order the aircraft to cover the nonstop flight from Buenos Aires.
Toronto and Montreal: both served from JFK.
In Latin America they flew to Bogota, Panama, Guayaquil, Lima and Mexico (on their Los Angeles route), Cancun, Caracas, Porlamar, Sao Paulo, Rio de Janeiro, Santiago and also Cordoba (as a stop to Miami). Also you can see them from time to time at Aeroparque Jorge Newbery when EZE was closed for fog some flights from Lima or New York would land in AEP.
Why they got rid of the A310's. Perhaps lease fees, however, the management style of the previous administration was hard to understand. There were frequent schedule changes so that is why for example the A310 were constantly changed.