There have been several posts on coil failures on these car / truck forums but my coil failure was a little different so I will explain for the next guy . Others have had their coils heat up and that prevented their vehicles from restarting until the coil was cooled down . On my vehicle the engine would sputter after things warmed up and the engine was pulling hard as in climbing up hill . The engine ran fine when it had only a light load . I suspected the more normal ignition problems , points , cap , condenser , rotor , plug wires , timing , plugs and carb adjustment and vacuum advance . After looking at all of those possible problems I realized that it was probably the coil as It happened after warm up . I replaced the coil and all is well again . Afterwards I remembered a faint occasional oder when driving of a hot electrical smell . When I was having problems I didn't think to touch the coil to see if it was too hot , but it must have been .