Pencil test: https://books.google.com/books?id=ho9kKynnWHkC&pg=PA185&lpg=PA185&dq=%22Igni tion+coil%22+%22pencil+test%22&source=bl&ots=yIH0XXaAjG&sig=bY1Ew4oHXr8bQSRJ BpDSs-ohsbg&hl=en&sa=X&ei=5dkyVYTGEoLSsAXi1YHwCg&ved=0CBkQ6AEwAQ#v=onepage&q =%22Ignition%20coil%22%20%22pencil%20test%22&f=false