All the others looked practically new (other than the same light surface rust & dirt/oil on the exposed ceramic), much like this one would if its electrodes were the normal shape. The truck only developed a noticeable miss yesterday, so today we changed the plugs & wires, and cleaned the cap & rotor. Now it runs just like it did a few weeks ago - perfectly!
But I can't figure out what caused this... If you have any ideas:
http://classicbroncos.com/forums/showthread.php?t=152008
![sparkplug8.jpg All the others looked practically new (other than the same light surface rust & dirt/oil on the exposed ceramic), much like this one would if its electrodes were the normal shape. The truck only developed a noticeable miss yesterday, so today we changed the plugs & wires, and cleaned the cap & rotor. Now it runs just like it did a few weeks ago - perfectly!
But I can't figure out what caused this... If you have any ideas:
http://classicbroncos.com/forums/showthread.php?t=152008
[url=http://www.supermotors.net/registry/media/830768][img]http://www.supermotors.net/getfile/830768/thumbnail/sparkplugdiag.jpg[/img][/url]](https://www.supermotors.net/getfile/771462/fullsize/sparkplug8.jpg)