[T3] ignition wire resistance

[Jim Adney]

On 14 Oct 2011 at 9:43, crash 69 wrote:

> Had an incident yesterday where a spark plug came loose (fairly new plug).
>  I put it back in and found the wire had a crack in the boot.  So, I put an
> old wire back on that #2 plug and I'm still having a misfire type symptom.
>  The old wire checks out fine, but it's much higher resistance (by design)
> than my current set of wires.
> 
> Old wire: about 9000 ohms per foot
> new ones (bought 5 months ago); about 400 ohms per foot
> 
> So, I've got 3 new ones and 1 old.  Will this difference in resistance cause
> my symptom or is it something else?  Spark plug looks perfect.

Starting sometime in the mid-60s VW started using metal conductor SP 
wires with lumped 1000 Ohm resistors in the SP connectors. These are 
much more reliable than the old style resistance wire, but the old 
style carbon "wire" is fine as long as you can measure any resistance 
that's significantly less than infinity over it's length.  

The difference in resistance shouldn't cause a problem, just make 
sure that none of your wires have gone "open circuit." Check the coil 
wire, too.

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