hey guys ive got a problem with my 8v. when the ht leads are in the correct place the engine has a really loud knocking coming from the top of the engine but if i swap ht leads 3 and 4 over the sound goes but it mi-fires. any ideas on what this could be? had new ht leads, rotor arm and new dizzy on it to see if that would cure it no joy. the car has lost all power as well. i've moved the spak plugs aswell to see if it was a faulty plug.