Distributor problems

[nickmobile67]

Hi, I've hung around this website a while now, but I finally regestered! I have a little problem maybe you guys could help me out with.

My 67 mustang has a mallory dual point distributor. Last winter I had an ignition problem. The car would stumble and break up going down the road. Eventually it wouldn't even idle. First I tried replacing the condenser but it didn't help. I ended up putting on a new condenser, cap, and rotor and cleaning the points. It was fine for a while but last week my problem came back.
This time I replaced both sets of points and the condenser, I also replaced all of the screws with stainless steel ones. The problem is fixed again but I'd like to know what is causing the problem (condenser?) and what I'm doing right to fix it. With any luck, I'll find a way to keep it from coming back.

Also, is there any way to test a condenser to see if it's good? I still have both of the old ones (mallory brand). The new one is a napa echlin.

Any tips appreciated.

I did also notice that the new points already looked slightly worn after 5 minutes of use, but that was before I changed the condenser and SS screws and it was still running bad.

I also have a mallory coil with the factory risistor wire, but that is supposed to be enough.

 

[slapper]

The only condensor check I know of is to see if it's shorted to the casing.
(Continuity between wire terminal and case=shorted=junk). This would cause the engine to die/not start as there would be no primary ignition voltage developed. I do know that if the condensor is failing in it's capacitance cabability,(wearing out), the contacts on the points will be subjected to the induced voltage collapse of the primary coil windings without any cushioning from the condensor. They will wear much faster.
As far as the dual point- check to see if the points spring back closed with sufficient tension when you open them slightly. Don't manually open them too far, or the spring may loose it's tension. A weak spring may cause the point contacts to "float" as it's known, and this would lead to a irratic ignition spark-or stumble and break-up as you mentioned.
Check to ensure the mechanical advance plate operates freely through it's range of motion, and that the cam lobe on the shaft is in good condition and not worn or loose.
The stainless screws will be less prone to corrosion from ozone, and other than that they look shiny.
I always personally thought dual points were a little tricky to KEEP set up correctly. Use a good dwell meter.
Is there a reason you prefer the dual point distributor over a solid state primary ignition trigger? Just curious.
They used to be the hot set-up years ago before solid state, as you could set the advance points to trigger your ignition spark a few degrees advanced and take full advantage of a slower burning, higher octane fuel in high compression engines.

 

[nickmobile67]

Thanks for the reply. I've posted on some other forums and that's the best response I've gotten! I guess I'm old fasioned, I think the dual point is more friendly to tune for me, I like to be able to see things working. I've got the dwell dead on at 32* total. One of the sets of points I took out did have a weak spring, but changing points alone didn't help. Mechanical advance is fine and the shaft is like new, not worn. I changed the screws to stainless for just that reason you stated, they won't get corroded like the old ones in there were, possibly restricting voltage. Even garage kept and summer driven, the year old hardware didn't look so hot. Plus it's harder to strip out those little flat heads!

I put my test light on the distributor between the housing and condenser wire (with it hooked up) and it would connect every time the points closed, but not otherwise. I checked a few other distributors I had lying around and they all seemed to work this way, so I guess it is ok. It was (it's fixed now) acting like it had a short in it somewhere. I don't think it was the condenser doing it, but every time I fix it (twice now) it seems like I do simple things and it gets going again. Very tempermental. Maybe the stainless hardware (because of no corosion) will keep things working smoother. That's my hope now, that maybe the little corrosion buildup was keeping things from working like they should.

 

[pabear89]

when I do set mine, I disconnect one side and set it at 24-26 degrees, then do the other.
when you say 32 total is that 16 per side?
that may be why your flash burning the points.

i'd say it's worth a try.

 

[nickmobile67]

The mallory calls for 33* of total dwell (give or take 2*) and 26* each. I havn't checked each yet, but it looks like I'm pretty close. Besides, I've sense cured the problem (how I don't know) and havn't touched the points. I just wish I knew what's going on with it.