HT Lead shock

[maxstu]

I received a nasty electric shock from the HT lead running to number three cylinders. My hand brushed against the lead cap on the distributor as the engine was idling. Whats causing current to flow outside? Or is it normal? Perhaps dampness?
Ive deliberately touched all leads before without issues.
I removed and vusually checked the naughty lead. Looks fine. Then a continuity OHMS check reads approx 4000. Lead is 24 inches long.
Regards
Stuart

[bigherb]

Poor insulation. Other things that can make the insulation breakdown are too wide spark plug gaps, high resistance in the cables, using resistive sparkplugs when you don't need them.

[maxstu]

Poor insulation. Other things that can make the insulation breakdown are too wide spark plug gaps, high resistance in the cables, using resistive sparkplugs when you don't need them.

Hello Mike,
I hope you are well? Thanks for reply. In fact l had just checked spark plug gap moments before.
Apart from starting engine and touching each lead how do l know if leads are man enough still? Not doing that again
The shock sent a blow up the side of my head. A dagger through top of my heart and both left arm and leg aching for couple of hours. Fun eh!

[maxstu]

Also, how does one recognise resistive plugs. New one for me

[tobydog]

Look up the code on the plugs...

http://www.ngk-sparkplugs.jp/english/te ... index.html" onclick="window.open(this.href);return false;

[bigherb]

Yeah I've had a few belts of them.
Basically if the spark can escape then the leads need changing. Electricity always tries to find the easiest route back home, trying to jump the spark plug gap under compression is hard work if the insulation can't contain it then it will find the easier route. Resisitive plugs are markered with an R e.g WR7CC as opposed to W7CC

[maxstu]

Look up the code on the plugs...

http://www.ngk-sparkplugs.jp/english/te ... index.html" onclick="window.open(this.href);return false;

Cheers Tobydog. Nice easy to read info

[maxstu]

And l assume a continuity check is needed to weed out failing leads?
I understand spec. is approx 4000ohms per foot of lead?

[bigherb]

Depends on the leads you have fitted, VW used copper core leads with the resistor in the plug cap and then latterly also a resistor at the distributor cap end. Carbon cored leads are measured in resistance to length.