What Billy said is an excellent point. Before panic sets in might be a good idea to "get a second opinion".

Cant think of any logical reason to see what you are seeing. is the Moroso pickup wire shielded? Is the pickup wiring running near anything else electrical, particularly the water pump? Sometimes you can get some unwanted RF that will cause all sorts of crazy things to happen.

I missed the part about the arrow. Would definitely want it installed correctly with rotation. I assume they put them that way for a reason?