Hi. I just recently got back into model railroading and tried to run an MTH rail king Commodore Vanderbilt. The train ran, smoked, horn and bell rang and steam sounds in neutral. The problem is the engine doesn't chug. I haven't ran it for about four years. I did a reset to the factory settings, let the battery charge on the track around 12 v. for an hour like the manual said to. When the engine runs a constant steam sound is made. How can I get the train to chug again? Thanks.