My husband just replaced the motor in my car. When trying to get the timing right, he got the flywheel set, distributor in, and tested with the timing light. Nothing, no marks. He moved the timing light lead to the 3rd plug wire and we can see the marks great and the motor is purring like a kitten. Can someone explain why we can see the marks on the 3rd plug wire and not the 1st plug wire? I really want to drive my car, and the car runs great, but scared to because I don't know that the timing is right like this.