[T3] Spark Plug Cables...

[Jim Adney]

On 13 Mar 2016 at 3:03, J. Jonik wrote:

> How to know if spark plug cables are shot...or on the way out?  Ditto for plugs.

I replace the cables if the wire has become hard and stiff, or if it 
has cracks anywhere. If you still have the original dist end 
connectors, that screw onto the wire, replace just the wire, not the 
whole assembly, as those OE parts are much better and nicer than 
anything you can buy new today. Check the SP connectors to make sure 
the internal resistor has not gone open. I have bulk wire and new or 
used SP connectors. I also have new Bosch wiresets, but they need to 
be modified to work; they're not long enough. You need to make one 
longer wire.

As for spark plugs, it took me a LOOOONG time to understand what to 
look for when thinking about replacement. Look at the shape of the 
center electrode. The corners will be sharp and square when new, but 
they get rounded by spark erosion as they are used. A certain amount 
of rounding is acceptable, but they should be replaced well before 
the end of the electrode become hemispherical.

If your plugs get black and need to be cleaned, that means that 
you're not using the right heat range plug or there's a mixture 
problem.

> I ask because, after bad running...and thorough cleaning etc of
> distributor, and even the old trying other points, rotor, cap etc...to
> fix....just a jiggle and snugging up of the spark cables seemed to be
> what got the car running.     But I do that a lot...and clean plugs.

My guess would be that you're wiggling something else in this 
process. There are a lot of other wires in the SP area that get 
bumped when you do this.

-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************