Distributor Problems

[El Jay]

Here's the background: When I bought my '69 it had an Accel distributor. I don't remember what the problem with the distributor was, but I swapped it out for a complete MSD system; spark box, distributor, Blaster coil, plug wires; firing Accel shorty plugs.

My problem is, about every 4 months, or so, the carbon button in the distributor cap is burned up so I have to replace the cap & rotor; which is getting expensive.

So far, nobody has been able to give me any reason why this is happening.
I e-mailed MSD tech support & they said it may take up to 48 hours to get back to me. It's been over a week & still no response.

Doing a little research, I've learned that the spark plugs (when doing a tune up, I just replaced "like & kind") I'm using are non-resistor plugs.
Could this be the cause of my problems?

Any input at all would be greatly appreciated.
Thanx,
LJ

[neonlarry]

Have you checked to see if the rotor contact is making good contact with the button on the cap? If not put a dab of dielectric grease on the rotor contact and install the cap, then remove and check to see that the impression in the grease goes all the way to the metal of the contact.
Also check all your grounds carefully (shiny metal to shiny metal).

[VetteVet]

This thread was posted by slammed70 last year and he had the same problem. I found a forum where they suspected the plug wires for the cause. I never did get a hard fast fix on it. You might PM slammed70 and see if he found the cause. VV


http://67-72chevytrucks.com/vboard/s....php?p=2904910

[prostreetC-10]

As we all know....electrical can be the worst to diagnose. I'm wondering if a weak system can cause the build-up? I'm shooting in the dark here but have you taken out a plug, pushed it into the boot and held it against your block while turning over the motor? I have a complete MSD setup too. It really changes the energy of the spark. Each time my rotor hit that plug, it lit it up like the end of your cutting torch. It would be interesting to know if you are really getting a high energy multiple spark.

Seems like battery terminals corrode when there is a weak connection.

[El Jay]

Originally Posted by neonlarry

Have you checked to see if the rotor contact is making good contact with the button on the cap? If not put a dab of dielectric grease on the rotor contact and install the cap, then remove and check to see that the impression in the grease goes all the way to the metal of the contact.
Also check all your grounds carefully (shiny metal to shiny metal).

I already did that. I really appreciate you offering the suggestion, though. There has to be a simple solution that I'm just overlooking.
As a side note, you coming down here to cousin Jerry's in 2 weeks? We all met at Roseville. I had the ugly, POS long step.

Originally Posted by VetteVet

This thread was posted by slammed70 last year and he had the same problem. I found a forum where they suspected the plug wires for the cause. I never did get a hard fast fix on it. You might PM slammed70 and see if he found the cause. VV

I pulled the plug wires & checked the resistance. All were good, except one. My multimeter showed that it was open. I wouldn't think that 1 plug wire would cause all these problems; & the plug wires were installed the same time as all the other ignition parts.

Thanks for getting back to me.

LJ


http://67-72chevytrucks.com/vboard/s....php?p=2904910

[1970 Bowtie]

This may sound simple but have you tried running a set of resistor plugs instead of the non resistor?

[El Jay]

Originally Posted by 1970 Bowtie

This may sound simple but have you tried running a set of resistor plugs instead of the non resistor?

That's my next step.

What's making me crazy is, although they are 3 years old, the wires, etc., don't have very many miles on them.

I'm kinda, sorta, in my mind, thinkin' about a cross country trip to visit my kids.
I don't really want to have to carry 3, or 4, extra caps & rotors (ever notice that rotor spelled backwards is rotor: how palindromic is that?) to change out on the road when the truck starts running like crap.

[mikajo39]

Just a possible thing running through my mind , maybe the non resistor type have,well, too little resitance, which makes an arc thats bigger than would be with resistor style plugs, resulting in carbon build up haha confused myself. My next step would be go buy some cheapy champion copper head plugs and see how long it takes till you have to change the rotor and cap etc etc

[Longhorn321]

Originally Posted by mikajo39

Just a possible thing running through my mind , maybe the non resistor type have,well, too little resitance, which makes an arc thats bigger than would be with resistor style plugs, resulting in carbon build up haha confused myself. My next step would be go buy some cheapy champion copper head plugs and see how long it takes till you have to change the rotor and cap etc etc

I would think increasing the resistance would make the spark hotter. An old timers trick to getting a fussy engine to start is to pull the plug wires off a little bit. This is supposed to make the spark hotter. Also, if you have your plug gap to small, the plugs will foul because the spark is not hot enough...bigger gap=more resistance. I don't know what more resistance would do to the cap and rotor tho...seems like there should be no arcing there so I don't know why there would be build up there.

[mikajo39]

well by arcing I was thinking it does happen just to a controlled extent because when the rotor strikes the terminal in the cap its gotta spark kinda like touching to jumper cables together just a lot faster lol . could be a lot of things hopehe gets it fixed whatever it is must be a pain

[WorkinLonghorn]

I'm not at all familliar with MSD but if the button is burning up then we know there is lots of arcing going on there,which will not happen UNLESS there is a space between the two contacts.
So you either have a weak spring under the button,the button is hanging up,or the bushings on the distrib are shot and the rotor is bobbing up and down.Of course it's kind of hard to picture the thing since I haven't had my distib off in a long time so I'm probably way off,except that I'm sure you have a gap in there.

[gizmo1]

the carbon button is causing the problem, get a special one from msd that will cary the current

[El Jay]

MSD doesn't make a replaceable button for the "small" (think GM "window sized" cap). They only make the button for the bigger HEI sized cap.
I checked that option 2 caps back.

But I do appreciate your input.

KJ

[fixit-p]

Originally Posted by El Jay

MSD doesn't make a replaceable button for the "small" (think GM "window sized" cap). They only make the button for the bigger HEI sized cap.

MSD makes this cap for point style dizzys I have on on my factory dizzy on my 69 it's seems pretty stout and the HEI style towers are also a plus IMO>>>http://summitracing.com/parts/MSD-8433/

[Longhorn321]

Originally Posted by WorkinLonghorn

arcing going on there,which will not happen UNLESS there is a space between the two contacts.
So you either have a weak spring under the button,the button is hanging up,or the bushings on the distrib are shot and the rotor is bobbing up and down.

Kinda what I was thinking too....could you lubricate the button where it moves up and down?

[El Jay]

Originally Posted by fixit-p

MSD makes this cap for point style dizzys I have on on my factory dizzy on my 69 it's seems pretty stout and the HEI style towers are also a plus IMO>>>http://summitracing.com/parts/MSD-8433/

That is the cap that keeps burning up the button.

I thank you for trying to help.

Originally Posted by Longhorn321

Kinda what I was thinking too....could you lubricate the button where it moves up and down?

Like I said in an earlier post, I put dielectric grease on the button & installed the cap; removed the cap & there was grease on the rotor.
I'll have to check the spring on the button tomorrow morning.
It's over 100 outside today. No need to punish myself more if I don't have to.

And, thank you.

That's what I love about this place; post a question about a problem & you'll get a whole mess of, "try this, try that, lookie at this" type responses.

Everybody tries to help.

LJ

[mikajo39]

It's over 100 outside today. No need to punish myself more if I don't have to.

Same here was going to get out and work on my truck today, not gonna happen today for sure. But it does make a good time to do some online research and beat the heat.

[El Jay]

I'm maybe 50 "road" miles away.
Heckuvalot closer as the "crow flies."

Just think east Contra Costa/Antioch!

[Longhorn321]

Originally Posted by El Jay

Like I said in an earlier post, I put dielectric grease on the button & installed the cap; removed the cap & there was grease on the rotor.

LJ

Sorry, I musta misunderstood. I thought you just put grease on the end of the button to see if it was making contact with the rotor. I was talking about where it slides in and out of the cap.

[mikajo39]

Dang that is pretty close!

[El Jay]

Originally Posted by Longhorn321

Sorry, I musta misunderstood. I thought you just put grease on the end of the button to see if it was making contact with the rotor. I was talking about where it slides in and out of the cap.

There sure ain't no need to apologize!!!!!!!
You were trying to help a total stranger.

Originally Posted by mikajo39

Dang that is pretty close!

Yup.
I'll be in your 'hood this week.
I actually get to work on Wed., I'll be at Homie Despot as my last stop Wed. afternoon.

[Longhorn321]

Hey here is another thought...when you go to check that spring, spin the motor over while you have the cap off and see if the rotor seems to be bobbing up and down like WorkingLonghorn suggested.

[El Jay]

I can do that!

The biggest thing that is making me crazy is this whole system don't have 10K miles on it. And yeah, I know, even new stuff can be "bad".

[royo]

Originally Posted by El Jay

MSD doesn't make a replaceable button for the "small" (think GM "window sized" cap). They only make the button for the bigger HEI sized cap.
I checked that option 2 caps back.

But I do appreciate your input.

KJ

?? a msd dist should allready have the good button in it right . The one i just bought has it in it

[Longhorn321]

Originally Posted by El Jay

I can do that!

The biggest thing that is making me crazy is this whole system don't have 10K miles on it. And yeah, I know, even new stuff can be "bad".

I hear ya. I'm curious now tho so you gotta post what fixed it.