<VV> misfire (technical)

[Sethracer at aol.com]

In a message dated 10/22/2006 2:48:25 PM Pacific Daylight Time,  
kovacsmj at sbcglobal.net writes:

I  then discovered that when I checked with the timing light on 2 & 6 that  
there was a steady pulse. However #4 had a steady pulse only near the  
distributor and an interrupted pulse near the spark plug. It obviously was not  firing 
all the time. What the heck is up with that?

The wires are brand new 7 mm from reputable vendor. Is there  a possibility 
the wire is broken internally? The plugs are also new  r44.



It is possible that the wire is bad (even if new). There are a few things  
you can try. Do you have the old wire set? You could substitute the old #4 or #6 
 wire for the suspected one and see if the miss stops. There are two wire 
failure  modes, either of which will cause a failure of spark. First, the wire 
can be  internally broken - usually resulting in a very high ohms rating vs. the 
other  wires. An ohm meter will tell the tale. Usually though, the plug wire 
will show  now pulse, even right next to the distributor cap, since the 
electricity has no  where to go. Second, a wire can be shorted to ground somewhere 
along the length  of the wire. This can happen when placed in the clips that 
restrain the wire  underneath the belt. In this case, the spark goes to ground 
and never makes it  to the plug. It would much rather take the "short" route to 
ground, than jump  the high pressure gap within the combustion chamber. - 
Seth  Emerson