Qingdao

iTrader: (3)

Why does my distributer have 4 condensors???

I get the two that go to the points, but what do the other two that go back into the wire harness do?



I recently put some new points in and bought two condensors and a cap (I didn't know at the time there are 4 condesors). Now I have a tacometer that jumps around. It will move at random 1k. I also have very weak if no spark at all.

The ignition worked fine before I started messing with it (turns out my original problem was just a gumed up carb from non use over the summer). So my problem now has to be in the points that I set or a nicked wire I missed or the fact that the other two condensors do something and being that I replace the other two they got jelous.


I am running (if you haven't guessed) a 12A 1979 points ignition on the factory 79 wire harness. Coils are about 1 yo. Plug wires are about 1 yo.

j9fd3s

iTrader: (3)

if the tach is jumping than something went wrong (duh).

i rebuilt the ignition on my 79, and i also had more condensers on the distributor than shown in the diagrams, there were also more condensers than places to plug them in.

i don't recall but i think i ended up with 3?

Qingdao

iTrader: (3)

Could these condesnors have something to do with the weird trailing fire on the SA's?

I read somewhere that the trailing doesn't fire 100% of the time on this ignition.

j9fd3s

iTrader: (3)

nope, the trailing thing is done somewhere else, although right this second i don't recall where

Qingdao

iTrader: (3)

Couple of things... Weak battery and bad leading coil.

I don't see how a coil would cause a jumpy tac, but that could be what the extra condensors do.

No local parts stores carry condensors in stock (the parts jockeys didn't even know what an "ignition condesor" was) So I've gotta wait for the mail to get the new condensors, but it does fire up now.

j9fd3s

iTrader: (3)

its been a while since cars had condensers!

gerald m

The condensers job is to keep voltage spikes stable ,to absorb high voltage on spikes and to release voltage when voltage is low ,,eg, when car is idling with lights and heater on . that said the car should run equally well with or without condensers , The job of the points condenser is to keep the current stable when the ignition points break ..eg. if there was such a thing as a perfect points condenser the points would never burn or pit , An under active condenser will burn towards the arm part of the points contact , an over active will result in a burn from the points arm to the power positive side ( Look at the points and decide which contact has a burned pit and which side has a high spot deposit

, If the alternator doesn't have a condenser on it , then it is possible that one of them controls spikes from the ignition power wire .or the alternator sometimes they are wired into the + side of the coil to ATTEMPT to suppress radio static but were never proven to work and in my opinion never did . Hope this makes a bit of sense , if they are in place they should be grounded by the mounting slot and not left to just hang . don't know the specs but usually the air gap on new points is around 18 thou to re gap used points that have been filed go a little more up to 22 thou . hope this makes some sense . Gerald

There are different sizes of condensers as far as voltage and capacity goes so make sure you are getting the right ones .

Qingdao

iTrader: (3)

^^^ that furthers my belief that the two extra condesnors have to do with the tac issue.

And If your condensors are bad on a motorbike it'll drain the crap out of your battery and you'll scratch your head for a few days tring to figure it out.

Jeff20B

iTrader: (13)

I wonder when NOW would be a good time to upgrade to electronic ignition. Hint hint. It makes upgrading to direct fire a lot easier, and you know how much these carbed rotaries like direct fire.

Your 79 has semi-firing trailing. This is to keep a rich mixture going into the thermal reactor so it can burn the HCs but just causes other issues like poor mileage and less power. If you have an aftermarket exhaust like a header, the semi-firing trailing can be eliminated.

So under some conditions, you're only getting one spark (leading) per rotor face or only two sparks per engine rotation (one per chamber). Compare this with direct fire where you get three stronger sparks per chamber (two leading and one trailing) or six per engine rotation. So that's 2 vs 6? I'll leave you with that.

Qingdao

iTrader: (3)

Yeah, but I'm a troll/caveman.

I'm putting my electronic distributer on my turbo project. Because that car is gonna be real reliable....

gerald m

you could probably do the change over that Jeff 20b is hinting at for a couple hundred bucks and it will love it ,, I'm a caveman also but I know a good thing when I see it .

At least think about it and get out from under that darn rock . not very often I can say that as I'm usually the one under the rock !!

Jeff20B

iTrader: (13)

Hmm, you're gonna lock that distributor, right? Try semi-locking instead so it only goes to 10 degrees max. Then at idle it returns to zero. It should make starting and idle quality a lot better while still protecting the engine in boost. The way to do it appears easy enough. You just take it apart. Add some some steel (weld) in the slot at the outer edge while leaving some room for movement.

As for needing an electronic dizzy for your SA, ask yourself how much you love the car and enjoy improving/driving it sometimes. Most SA owners are pretty fanatical about them and don't want to risk changing anything too much. But if you've already changed the exhaust and if there's no emissions testing in your area, then there is no reason to put up with the lesser of two possible igniton choices. Heck even the 80 SA has a crappy early version. Just find yourself a cheap 81-85 dizzy and do a direct fire swap while you're in there changing the wiring and stuff. Once you've removed the ballast resistors and complicated points wiring, the electronic stuff is super easy to get going if you have any kind of apptitude and hands that work/can use a multi-meter. But you already know all that. Just trust that it's a good worthwhile upgrade and ask questions if you get stuck.

Qingdao

iTrader: (3)

I already got an electronic distributer. I juat dig on the points.

The turbo car is my 84; to which I have no quams upgrading or what not. The SA is gonna stay my DD.

Other than this issue I haven't had anything less than perfect running from the points. If it ain't broke don't fix it. Shoot cold starts are quite impressive; compared to any car.

Jeff20B

iTrader: (13)

I like it when they start in a half crank even when cold. Must be a rotary thing.

Qingdao

iTrader: (3)

... So I figured out my issue. Corrosion on a 35 yo fuse.

I still don't know what the heck the strange condensors are for, but I fixed my problem.

fearfulear69

Im have in the same problem whats a yo fuse

rwatson5651

iTrader: (5)

Thats troll/caveman talk for "years old". 35 yo = as old as his car!

fearfulear69

Ohh ok. Im just wondering what kind of condenser s are the two most viable? I replaces the two that go directly too the contact points little one for leading bigger for the trailing is this right? And what are the other two and whats size are they or part number? They seem too be same size as the trailing one that goes too the contact point.....

Qingdao

iTrader: (3)

I don't know about sizes... they were all physicly the same size.

Tell you the truth I unpluged the two that don't go to the distributer when I was undergoing this, and I didn't notice the first lick of difference. Not a stumble not a chirp.

I think your wire nut on the key switch is causing a loose connection (much as a rusty non conductive fuse would). I'd try a new key switch before anything.