What causes carbon build up on dist rotor??

[Rasp933]

Whats up people.

Once again I am having the same issue .miss fire stalling.

When I checked the rotor n cap I see carbon build up.can sumbody explain please?

.

[datzenmike]

Well, high voltage travels through the rotor and onto the cap contacts. They come close to contacting and the spark just jumps this very minor gap. Any electrical spark will erode or etch the place where the spark jumps to and leave a mark. Over time this will look like a carbon build up.

 

Cheap quality caps and/or rotors may even rub and wear off material that looks like dust.

 

There is also 'carbon tracking'. This is where the spark takes a short cut to ground across the surface of the plastic cap, the rotor or even from the center coil wire t the negative terminal. This will leave a dark etched mark Effectively it burns a track in the surface and once established will become easier to jump again next time. The cure is to replace. To prevent this make sure that your high voltage spark sees only the spark plug as the easiest path to ground by using good quality parts and keeping them clean and dry.

 

 

Maybe a picture will help.

[banzai510(hainz)]

justr sand it off and clean it.

 

missfire stalling is not going to be to much cap and rotor. I have been using my cap and rorot for about 8 years now with no proplems.

If anything you still have points and condensor make sure the dizzy bushing is tight so the shaft dont wiggle and make sure the intake and valave lash is tight, carb tight. ck the timming chain/cam if the cam is still timmed.

 

carb still good? or worn out?

 

During a hard rain or after a snow melt off where high humidity I would soemtimes get water under cap.

Dry off then all is fine.

I run the old Blue Streak copper contack caps(NLA that I can see)

[Rasp933]

Iam running accel coil wit duralast caps n rotor.could it b the cheap quality of duralast?

[banzai510(hainz)]

depends on the accel coil. and your still running points.

If a Super Stock you still run the stock ballast resisitor also. personally should have just buy a stock jap coil.

 

If running a SUPER Coil you need the stocl ballast and the resisitor that comes in the kit(.85 ohm resisitor in series with the stock ballast resisitor to keep the current down OR it will arch the shit out of the points.

 

dont know nothing of Duralast but I try to get Jap parts or Standard Motor products has a brass contack cap.

 

i think most times its condensors not grounded right or points issues.

 

I really never seen a cap go bad, well once with body else the center probe was worn down or fell out.

 

Find a EI conversion or go matchbox is the best for reliabily.

[Rasp933]

I have electronic dist.wit gm ignitor. And no ballast resistor.

Stock ignitor took a crap.according to oreillys auto

[Rasp933]

Dizzy is outta 79 80 nissan 200sx

[MikeRL411]

You may have a 43 year old distributor cap although I doubt it.  Remember, the high voltage from the coil get to the rotor by way of a carbon patch in the apex of the distributor housing.  Check it's condition for wear.  Probably a good idea to replace anyway and eliminate one more failure probability.

 

By the way, if moisture gets into the distributor a quick blast of WD40 will displace the moisture and permit a start.

[Rasp933]

New caps n rotor .new coil new wires new ignition pickup.but iam using gm ignitor with it.also using ballast resistor.but stalls.

[Rasp933]

Could it b the alternator?

[datzenmike]

Just keep replacing things until it works.

[Rasp933]

Lol

[MikeRL411]

Just keep replacing things until it works.

 

 You have no idea how much this sounds like the poorly trained "mechanics" who keep changing the most expensive parts [like the computer] until they find the bad capacitor [for 50 cents] and keep charging all the way.

[Ranman72]

try to get the copper contact cap and rotor not the shiny metal ones 

and no pics = FAIL

[ggzilla]

What causes carbon build up on dist rotor?

It's normal use that does it. Even the best genuine Nissan cap or cap with brass contacts will do it. It is not a problem. Just scrape the metal down a bit with a screwdriver and put it back on.

[banzai510(hainz)]

just to remind you a Accel Super STOCK coil needs a resisitor if I remember right. it will get hot. feel it next time running. I dont think its designed to run off straight 12-14 volts.

the newer 78-79 nissan and MSD Blaster will run fine .As they are designed to run w/o a resisitor.

 

I seen people run the stock coils with out a resisitor but one should NOT run them that way.