The Stovebolt Site Forums The Shop Area The Electrical Bay Burnt distributor cap electrode

The truck failed to start today . . I figured it was no spark and pulled the dist. cap .
What a surprise the center electrode had burnt right away up inside the core of the cap. The spark was having a hard job getting thru all the air space !.
Fortunately I had found a new cap at the last swap meet I went to , swaped that onto the truck and all is well again .
But how did the center electrode get so burnt away in the first place , this cap is only 2 yrs on the truck (20,000 miles) .
I have not experienced this before , has anyone any clues as to why this happened ? I'd like to change what ever is the cause .
The truck is 12V now , the cap was a non Delco replacement item , as is the new cap.
12V coil with external resistor. :confused:

The center spring of the rotor must be bent down. That would leave a gap that would cause burning the cap.

Thanks kedso , I'll go and check that right now .

Update ,, The spring on the rotor was very low ,, I had to lift it up a 1/4" before it contacted the cap electrode .
Good call kedso , thanks .