Cap and rotor life?

[Jes]

This is the cap and rotor I just took off my '93 with 157,000 miles on it.

That cap and rotor have about 20,000 miles on them and I installed them in April of 2002. I'm just wondering if that is normal wear in that amount of time?
It ran fine before and my gas mileage has been very good, the idle is much improved now with the new parts though.

Jes

 

[pancake]

Those look a little worn for 20k miles IMO.

 

[AZ Jeff]

What's all the brownish colored dusty looking deposits? Is it some of the plastic after being ground up, or is it carbon tracking?

Either way, there's a lot of it, and that's kinda weird for 20K miles.

What brand of cap and rotor is that?

 

[Jes]

All the brown stuff is dust and dirt. It's the black crusty stuff that that I'm wondering about.
It's a Conrad Industries part. I installed that to replace my Mopar cap and rotor which lasted maybe 12,000 miles, incidentally.
Maybe it's just how I use my vehicle?

Jes

 

[Weasel]

Yeah looks pretty worn. I just replaced the original cap and rotor on my 89 with 159k. Havn't really noticed any improvements with the new cap/rotor though.

 

[8Mud]

I usually replace two distributor caps and rotors, to every one set of plugs. Ford makes a cap without the air vent, that seems to help some.
I sometimes just clean the oxidation off the electrodes, but once the coating burns through, they re-oxidize pretty quick.
A very light bead of silicon between the cap and distributor and a dab on the top and bottom vent holes. Will help keep splash water/mud, out of the distributor. A little scraping and a brass brush, will remove the silicon pretty quick.
I live pretty far north, had an XJ that would miss like crazy every time it got warmed up. Was a little moisture in the bottom of the distributor, that would freeze and then defrost and condensate when the motor warmed up. Ran just fine as long as the temp was below 32 F and the motor was cold. Drove me crazy.