Arching in distributer cap

[crankedup]

My car is running very rough and I have noticed that inside the distributer cap is signs of burning surrounding two of the four pickup points. Any ideas as to what may be causing this?

[GreenV8S]

It can be self-promoting since the arcs leave tracks which make it easier to arc in future. Maybe it started with damp, or a stress crack, or just surface dirt.

[stevieturbo]

Maybe its just knackered and needs replaced !!!

[rev-erend]

The cause is easy .. it's a high voltage spark..

Not sure you want to cure the cause though..

Replacement of the cap sounds like a better idea.

[crankedup]

Thanks guys, I feel an new distributer cap is on its way.

[Wacky Racer]

Many years ago my Triumph Spitfire broke down on the roadside....the cause was a hairline split in the plastic, causing arcing... a new cap at less than a fiver cured it..

[phumy]

Wacky Racer said:

Many years ago my Triumph Spitfire broke down on the roadside....the cause was a hairline split in the plastic, causing arcing... a new cap at less than a fiver cured it..

Having a pencil in the car will help to eliminate tracking across hairline cracks. If you rub the pencil lead across the area of the hairline cracks it will stop the "aching" effect for enough time to get you home, to be able to fit a new one.

HTH

[crankedup]

Fitted an new rotor arm and condenser today and it made no difference to the ignition problem. Expect a new distributer cap tomorrow and hope that cures the spitting back and misfiring.