Rapid oxidation build up on new distributor cap

[oldsohc]

I picked up a 96 Civic as a winter beater this fall, with the D16Y7. I gave it a good tune up a few weeks ago, which included new Bosch cap and rotor, Denso wires, and NGK plugs. The old components were very worn, so I had a feeling the ignition coil was probably exhausted too and was planning on replacing it with my next Rock Auto order.

Two days later the car died on me and left me with a tow bill. Of course I had a good feeling it was the ignition coil. I ran some quick diagnostics and confirmed it was in fact a shorted coil. I needed the car back on the road ASAP, so I grabbed a used coil from a lower mileage 2000 Civic at PicknPull and had the car running again.

Fast forward about 2 weeks, I finally get a new aftermarket coil. And I go to install it, which requires me to pull the distributor cap off. In doing so I notice a substantial amount of white oxidation/build up on the contacts inside the distributor cap I had just installed 3 weeks ago, with only about 1000 miles on it so far. So much that bits of the build up were falling off the contacts and settling on the bottom, inside the cap itself. The distributor is the factory Honda TEC, and the Bosch cap and rotor appear to be OEM quality, marked Made in Japan on the box and the parts them self. The new Denso wires, I have tested at 1.53K ohms (shortest wire) to 2.35K ohms (longest wire). Thoughts?

 

[irad]

If the ignition system has a capacitor/condenser I would change it.

 

[BigD1]

Check the cap seal. It should be on the distributor. New caps don't come with seals, at least not the ones I have bought over the years.

Aluminum contacts? Bosch made in Japan cap for my pickup has aluminum contacts.

NAPA Echlin has brass contacts and terminals. They cost a little bit more than the aluminum contacts/terminals. Made in Mexico the last one I bought.

 

[andyd]

Did the original cap have brass contacts?

 

[WDB]

Have seen this problem in the past.....Fixed using a better quality cap with brass contacts and a very high alkylide (sp) composition cap..

NAPA Echlin has brass contacts and terminals and is the only way to go...Brass is a better electrical conductor than aluminum. Contacts corrode quickly due to the arc that exists between the rotor tip and distributor contacts.....Ozone is created inside the cap anytime an electric arc exists. Be sure the cap is ventilated......Usually the tiny vent is designed into the cap or in the distributor Don't add another vent. The stock vent should work.

 

[oldsohc]

No condenser as far as I know.

The cap came with a new seal that I lubed up with silicone grease before installing.

Yes looks like the Bosch cap has aluminum contacts. Not sure what it was from factory.

Also the igniter chip has signs it may be overheating? The gel/silicone stuff that they pack inside them appears to be leaking out the rubber plug. Will try a different igniter, along with the new coil pack and check the cap condition in a few hundred miles.

Thanks all!

 

[oldsohc]

Here is the oxidation on the newer 'made in Japan' Bosch cap with only 1000 miles.

 

[oldsohc]

Here is an old Honda TEC cap, installed since factory with 125K miles. Wear looks pretty low considering the mileage. There is considerably less oxidation "dust" in this cap, than the one I had only run 1000 miles on.

Does not appear to be brass/copper.