This looks to be the kind of liquid smoke unit your locomotive has.
http://www.traindoctor.com/service/images/8738-200.jpg
The liquid does not crystallize like the pellets do. You may need to add 5 or more drops of smoke fluid if the unit is dry. Look at the left side of the locomotive and make sure the smoke unit piston is being pushed all the way by the drive rod, and returns properly.  Add as many cars as you have to the loco and turn the transformer throttle up to give the smoke unit more voltage. If the smoke is still not puffing properly, the smoke unit may need replacement.
The older smoke units were not fan driven, only the relatively recent units are.

Larry