There are two kinds of Pertronix systems- - - - -the ones that have failed- - - -and the ones that are going to fail soon. There is a coil spring and a phenolic plastic button under the grease cup below the distributor body that puts pressure on the shaft and compensates for minor wear. Without the spring pressure of the points present, especially if the grease in the housing has solidified, the tension spring will not be able to compensate for wear, and the shaft will get sloppy. That will make the ignition timing between cylinders erratic, and the idle surge will happen. Use the Pertronix parts for sinkers the next time you go fishing!
Jerry
