Green corrosion inside distributor

Blackstack · Apr 30, 2018

My Dad is always complaining about a green corrosion that keeps coming back after time and turns into a miss. He is sometimes able to clean it up and sometimes not and buys a new distributor. He just chalks it up as "they just don't make distributor caps like they used to" but I suspect something else is going on. Any ideas? He's running carbon core wires and I assume resistor plugs.

Steve@Advance · Apr 30, 2018

I suspect the problem is moisture, which in turn causes the corrosion.

The corrosion is likely not the problem. When moisture gets in the distributor, it tends to condense on the underside of the cap. The moisture is somewhat conductive and starts the process of "carbon tracking", which will short between the terminals causing a missfire, or track to ground stopping it all together.

Be sure everything is in place, some have a dust shield under the cap. If it's missing the cap won't fit properly, water will get in. Check the grommet where the wire goes through the distributor housing.

Also be sure the distributor is protected from rain as best as possible. If it lives outside, you can cover it with a plastic cut off jug, or form a sheetmetal deflector to shed water. And be sure the thermostat is working. Sometimes moisture condenses from the crankcase if there is excess moisture in the oil.

David G · Apr 30, 2018

You might want to pop cap off once in a while and let it vent, I did that with my caps this winter.

old-9 · Apr 30, 2018

What tractor?

rustred · Apr 30, 2018

brass and moisture makes green corrosion.

Michael Soldan · Apr 30, 2018

Here is where WD 40 will do what it is intended to. WD 40 is not a lubricant but a (W) Water (D) Displacement formula, spray with this product to remove moisture and leave a coating of the formula on the distributor and all its parts, may need to do this a number of times per year

Bob · Apr 30, 2018

(quoted from post at 16:12:57 04/30/18) My Dad is always complaining about a green corrosion that keeps coming back after time and turns into a miss. He is sometimes able to clean it up and sometimes not and buys a new distributor. He just chalks it up as "they just don't make distributor caps like they used to" but I suspect something else is going on. Any ideas? He's running carbon core wires and I assume resistor plugs.

Electric arcs make corrosive ozone.

And there's LOTS of electric arcs going on inside a distributor cap, as the tip of the rotor and the corresponding high-tension terminals don't physically touch each other and there's an arc there at each and every spark.

Lots of distributor venting schemes have been tried, with varying degrees of success.

In some applications, there's actually "fan vanes" on the rotor to stir up and exchange the air.

As an example, GM "small cap HEI's" and "Optisparks" had lots of issues with this, and had screened vents in the distributor "body" itself. Or lack thereof.

showcrop · May 1, 2018

It is the same situation as moisture in the hydraulic and transmission oil. A cold front following a couple of high humidity days, makes moisture in the air condense on the inside the same as it does on the outside. If the machine is run and worked for a couple hours daily it never accumulates.

Texasmark1 · May 1, 2018

Back in 1977 I bought a Toyota Corolla, black fastback (resembled the Ford GT), 20R 4 cyl OHC, 4 on the floor. Igniton was capacitor driven but not CDI. Rather than the points doing the switching, the points operated the gate (input) of a solid state device that did the switching electronically....good for a million+ operations with no contact degradation.

Current through the points was in the milliamps and not enough to burn off the crud.

Ever so often I'd be driving along and the engine would stutter and in some times just stop. I'd get out, pop the distributor cap and rotor, take a business card and run it back and forth between the point contacts a few times, put it back together and off I'd go......yepper, green crud on the card that isolated the contacts.

Green corrosion inside distributor

Blackstack

Member

Steve@Advance

Well-known Member

David G

Well-known Member

old-9

Well-known Member

rustred

Well-known Member

Michael Soldan

Well-known Member

Bob

Well-known Member

showcrop

Well-known Member

Texasmark1

Well-known Member

Similar threads