I'm not certain of which brand is on the vehicle but here is the issue. The contacts inside the cap and the rotor itself are building up some carbon or something that is causing a misfire. (It is white.) I cleaned the build up off the cap and rotor not 2 months ago. I read on a post that I should only rely on A/C Delco parts. Any thoughts?

 

A/C Delco plugs only for these things. The whitish stuff you see is aluminum oxide and yes it'll cause misfires. It's easier for the spark to follow the buildup to the base of the distributor than jump to the tower where the metal is missing. If you haven't replaced the wires they're important too. Personally I've had good luck with NAPA ignition parts but buy the premium line. I dunno if it still holds true but used to be cheap line used aluminum posts, high end used brass.

 

Regardless of brand, you want brass contacts, period. Yes, you'll spend more money for it but it will last so much longer.

 

I think it was an aluminum contact I cleaned. I do prefer to purchase things from NAPA.

 

white and hard like the build up you get on battery terminals?

 

Somehow its true. A/C Delco parts, (distributor & distributor rotor) didn't have this problem. I mean, based on my experience on them.

 

I dont remember seeing brass inside my ac delco cap. It did feel heavier that the aftermarket i had replaced. I didnt look close but my gut tells me they may be steel.

Ive been wrong before, the only thing I can gauruntee is that i will be wrong again.

 

You'll never see steel used as an electrical conductor. It has a high(er) resistance than copper or aluminum and can become magnetized. (BTW bronze is a copper alloy).