I have a 4-8-4 that I got with the Empire Builder set late last year and it has run very erattic from the begining.  It is not a Spectrum class engine.  I have tried cleaning the track and wheels by holdong to engine in place and let the wheels spin to no avail.  My local hobby dealer counter person told me he thought it may be a manfunction of the pickups.  Any advice/suggestions?

Thanks in advance
Gary in Oregon