My Willys 3A and 3B Community
3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: Spacecrab on January 05, 2022, 08:36:56 AM
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Hi guys,
I just wanted to ask what Points set you are using in your distributors?
I burning through a set every 4-6 months
The ones I can source locally don't seem to last very long and on closer inspection the tab which rides of the distro shaft is plastic
I believe originally it was a hard fiber right?
Any advice welcome, thanks
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I’m using Echelin (sp?) from NAPA. They are not the quality of days past but seem to function ok. Last set I got did not have the little lub capsule. I guess it’s not needed with the plastic tab.
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Standard Motor Products SMP are the best you can get.
They even have an upgraded version the SMP Blue Streak.
If you continue to burn points then perhaps your coil voltage is too high.
Do you run internal or external resistor coil ?
You may be running an external resist coil without a resistor inline and that will burn the points.
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What Oldtime said! X2
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Yes I'm running what I believe is a external Bosch unit (sticker is long gone)
I'll look into the resistor line, I have no idea what the electrician put in but I'll say that it doesn't look any different to the other lines so it might be that
I may have jumped the gun and bought some Autolite NORS points
Thanks guys,
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First off I am assuming you have a 12 volt system.
You need determine if it has internal resistance or external ballast required type of coil.
134’s were normally set up with coils having sufficient internal resistance.
A 12 volt internal resistance coil is basically a 6 volt coil with extra windings to create sufficient resistance so the points don’t burn up when hooked to 12 volts.
You can basically determine the type of coil you have by testing the amount of primary resistance.
Contact an ohm meter to the tower and the + or - post.
Internal resisted 12volt coil should read about 3 ohms.
What does yours read ?
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Thanks OT
Not sure if I'm on the wrong setting but I seem to get this reading,...
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....
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This guy does a good job showing how to test a coil.
Follow his directions and tell us what you come up with for primary and for secondary readings.
I can then tell you what your particular numbers indicate.
https://m.youtube.com/watch?v=FIx4dxew_UU
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Thanks OT that was really helpful
So I'm getting 4.6 on the primary windings in the 200 range & 8.1 on the secondary winding (20k range)
So does that mean I'm way over the 3 reading you mentioned?
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Sorry bout that.
I recently tested some coils for my dauntless and had those particular coil specs in mind.
According to the SM 1046 your primary resistance for a 12 volt F-134 should range between 3.9 and 4.2 ohms.
I’m sure it will function as is, but a reading of 4.6 primary is out of specification.
Basically the primary system has too much resistance which means it should not burn points at all.
However it will have weakened spark especially when starting.
The secondary numbers also give an idea for how strong the spark will be.
The higher the number the better the spark.(within spec)
Here your secondary is too low and out of spec.
It should range from 9400 to 11700 ohms of resistance.
Bottom line is that your weak coil is not causing your points to burn.
I’ll have to think what else may be happening here.
O.K. Here’s an idea. Are your point faces squarely aligned to one another?
Also if gap is closer than .020 spec that could be a problem causing short service life.
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How much of your system is 6 volt and how much is 12 volt?
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Thanks OT,
Strangely (and luckily) my 3B starts like a champ: that's one side that's never been a problem.
I see videos of CJ2a and older jeeps balancing choke and accelerator and warming I feel relieved I don't have to mess about like that each morning.
Mine is like a lighter, turns on and I'm off
The spark plugs do always seem to be dark black however: I just assumed I needed to stick a thicker spacer between the fuel pump and engine but I wanted to run a pressure test first. Could a weak spark mean fuel doesn't completely burn in the combustion chamber leaving the plugs filthy?
@Scoutpilot: as far as I'm aware the starter motor, alternator, signal stat & coil are all 12 volt, the rest is pretty much original but I have to admit I'm no electrician and pretty much leave it to others to sort.
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Generally spark plug fouling is a symptom of bad rings, worn valves and is most commonly caused from improper fuel mix.
But yes a weak spark will exaggerate any of those conditions.
The only other major component is the condition of the points condensor.
I hear nothing good about the new replacement condensers available.
I only use NOS condensers and further more I test them all and mark their specific capacitance on each one for future reference.
Here again the SM1046 states they should have .25 to .28 microfarads of capacitance.
And yes a bad condenser can prematurely burn points.
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OK I'm really learning something
I have avoided the electrics side of the car, it's always seemed like black magic to me haha
Question: an electrician once recommended wiring two condensers in parallel suggesting that these days they are of bad quality and doing that would somehow divide the load between them and stop them from being damaged
Is that right or another misconception?
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All I know for sure is that the condenser is specifically used to prevent arcing at the points whenever the points open. That said I don’t even understand why the points arc when you manually open them.
If you attached two condensers in parallel it seems to me that would serve to double the total capacitance and there by the total capacitance would be outta spec.
Anyone else know ?
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I am a little late to the party, but I had the same issue and converted to electronic ignition. Now I am not suggesting you do that, but something interesting I recently come across is I have an original 1937 Chevrolet. It is still six volt and it does not burn up points, so I went back to my jeep ballast resistor and was getting 8.5 volts. I believe that was my issue and had I been thoughtful enough then, I would have tried something different and retained the points.
I believe there are three typical issues with the modern points parts. 1. Ballast resistors do not sufficiently reduce voltage. 2. The points wear block is to soft, wears to quickly, allowing the points to close up. 3. Condensers do not sufficiently buffer the voltage spikes.
I would look for new old stock points parts and check the ballast resistor, or get a Ron Francis voltage reducer and supply a straight six volts to the ignition.
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Yes if your coil does not internally reduce to sufficiently low enough voltage via resistance readings then you need an external ballast. Ballast can vary quiet a bit because they were often designed for specific ignition systems. So if you run a ballast you also need to test to make sure it will reduce voltage to about 8 of 9 max.
I suspect that’s the idea behind the 8 volt batteries you here of.
Somewhere around 8 or 9 the max voltage that will produce the hottest spark without burning up the points.
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Right I'll have a look into that!
Does it wire before or after the coil?
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Before.