Toy train operating and collecting

My Atlas wye switch is thrown automatically within a double loop, tossing the train to the outside loop, then next pass to the inside loop, etc. It gets it's electric from a series of capacitors, resistors, etc, Bob N helped me with.  It works great. But...it sparks when going from inside to outside, but not outside to inside. It sparks enough that is easy to see and causes a momentary little " glitch " in the electrical system. What would cause this and how could one correct that problem?  Thanks to all responders, Jake

PS. Post War ZW powers the whole show, only one transfomer involved on this layout.

Where is it that you are seeing the sparks, Jake?

The sparks are down near the trucks by the pickups, Pretty fair sparks. Jake

If the pickups are sparking, that's a clue that the problem is in the track power, not the switch-motor electrics.  But, just to be sure, with the train not there, try touching a wire between each insulated control rail and a regular outside rail, to see whether the points move properly, without (more than a very little) sparking.  You could also push a car across the trackwork by hand if you like; but it might be a little harder to see any sparks.

If that's okay, then describe for me how you have the track powered.  Is there a change from one transformer output to another as you change loops?  For example, is one loop powered from the A output and the other from the D output of the ZW?

Try putting the locomotive in neutral and then pushing it slowly by hand through the trackwork with the voltage on.  You might be able to see where the event is happening that way.