LYNN – MBTA officials insist a grimy, junk-filled elevator in the commuter rail garage tops a list of lifts that will be repaired and placed back in operation.With no elevator access to the train platform running from Munroe Street to Central Square, disabled and mobility-impaired riders in Lynn who want to board a train ride a handicapped-accessible bus to the Swampscott commuter rail. Handicapped riders must get off the train in Swampscott for a free bus ride to Lynn.Massachusetts Bay Transportation Authority spokesman Lydia Rivera said the broken elevator near the garage’s Munroe Street entrance will be working by next Tuesday or Wednesday.”We will have it back in service no later than then. That’s a priority,” Rivera said.A rust-streaked sign mounted to the elevator informs riders it is “Temporarily out of service. See station personnel for assistance.”A second elevator located under the platform between Union and Mount Vernon streets has been closed for years and the MBTA has no plans of reactivating the lift now that bus service has been moved from Mount Vernon Street to the garage.Workers with KONE, Inc., the MBTA’s elevator maintenance contractor, began stripping parts from the Mount Vernon elevator Friday to use in repairing the Munroe Street elevator.The agency is launching $176 million to repair and, if necessary, replace its 127 elevators and 167 escalators in its Eastern Massachusetts stations over the next four years.MBTA officials said 99 percent of transit system elevators were repaired and operating in the first nine months of this year and 98 percent of the system’s escalators were working.”Customers deserve quality service and that includes fully functional elevators and escalators that customers can confidently use,” said MBTA General Manager Daniel Grabauskas.The commuter garage has two working elevators serving parking levels. The Fire Department periodically responds to malfunction calls concerning the elevators.”The elevator gets stuck a lot,” said Fire Chief Edward Higgins, adding most of the calls involve pranksters halting the lifts by pushing their emergency buttons.MBTA officials remind elevator riders to stand clear of elevator doors when riding the lifts and use the elevator intercom or telephone in case of an emergency.