There have been so many excellent guesses. I tried to check this one out
by placing an ohm meter across the insulator areas that would get
contaminated by this sort of thing but there was no reading.
Here is another clue: When the plugs have been really bad, I can place a
timing light on the ignition wires and it will blink intermittently. In
addition to that when it would flash, I would also hear an extra pop
from the tail pipe as if it were firing on that cylinder. My current set
of plugs are not so bad where I can do this measurement yet but I did do
this in the past. What would cause intermittent flashing on a timing
light? An open or a short? Also I noticed this affect was on the #3 and
#4 plugs, right in the center of the engine.
>Here is a guess. I have read that some fuel additives will cause near
>invisible deposits on the spark plug insulators. Some of these can be
>electrically conductive. Perhaps using to much lead substitute?
>Greg Gelhar
>1973 TR6
>1980 TR8
>Osseo, MN
|