I gave my D16Y7 in the winter beater a ignition tune up this fall. Cap and rotor were swapped out for new Bosch ones, made in Japan supposedly. A couple weeks later the factory coil gave out, so when opened up the distributor again to change out the coil I noticed the dizzy cap contacts were already starting to oxidize quite rapidly. About 1000 miles on the new cap. And there is already a bunch of oxidation dust/particles being generated and falling off into the cap. I have attached photos, the first being the OEM TEC cap from factory with 125,000 miles and the 2nd,3rd photo is the Bosch I had just installed earlier this fall with only 1000 miles. Notice how the new Bosch already has just as much oxidation dust/particles settled in the cap as the original.

Would this have been from the failed coil? Or just bad quality parts? I was told that getting a brass/copper cap and rotor, like the NAPA Echlin would remedy this, but I'm curious what material the OEM TEC contacts are made of, they appear to be aluminum just like the Bosch. Thanks all!


OEM TEC cap from factory with 125,000 miles, looks not too bad


Bosch cap with 1000 miles, lots of aluminum oxide dust/particles already


Close up of a contact on the Bosch cap with 1000 miles, build up already quite substantial