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Discussion Starter · #1 ·
Hi guys, well after breaking down yet a again saturday I thought it time to get some advice.

It's a 41 Ford, original flathead though has been converted to run 12v.

Has the distributor that has two caps, one either side and normally a coil that sits on top, but has been converted to run with a modern coil through a balast resitor.

It will always start really well, engine runs and drives silky smooth, but after its all warmed up maybe after 20mins or so driving and then sitting ideling or in traffic it just cuts out, like turning a switch, no bad running, missing, just off!

I've changed the coil, as I figured it could be that, but has done the same with 2 new coils. Changed the balast resistor as I found that had a crack in it, but still getting the same.

So should my next point of call be the points and condensor you think?

Once cooled down after 20mins or so it starts back up with no worry.

Doesn't usually stop running whilst you're travelling along at a fair rate, though has once.

Anyone with any ideas?
 

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Discussion Starter · #2 ·
In hindsight, i know this is a pretty open ended question, with many possible problems. Just wanted some opinions, as my thinking is electrical, the fact it running fine one minute then just turns off.

I did check a lead on the head last time it wouldn't start and there was a spark, but looked very weak.
 

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Next job is clean the points and regap, if there not obviuosly shaged and pop a new condenser in there. that should eliminate that stuff, be good to use a known good condensor, as new dont allways meen good.
If it stops "like a switch turnd off" this would normally point to lecy stuff, as fuel probs normaly miss or cough or peter out rather than just off.
Check all the wiring from the switch to the coil real good.
Is it just the ignotion that goes off ? any other curcuits effected? There are curcuit breakers on your car (should be) it may be wise to check that the ignition is not through one of these. The ignition and guages (not the gauge lights) are not protceted by the curcuit breakers, just the light (all) cigy lighter and heater are off the breakers and therfore protected.
Martin.
Martin.
 

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Discussion Starter · #4 ·
Hi Martin, thanks.

There's no original wiring, and very little in the way of new wiring, I think the film company that owned it previously had it done.

So a very simple circuit, I think 3 fuses, one for ignition, 1 for lights, 1 for indicators, and thats about all the electrics it has.

When cut out, lights, indicators, stater etc work fine.

So points, condensor then see where i break down next :)

Should the condensor be a universal type one suitable for 12v/12v with balast, or should i be looking for something specific?
 

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Sorry for delay, For testing perpose I'd bung in a Lucas type condensor as fitted to Minis and Moggys and the like. I have used these on all types of stuff. Normaly when changing ignition stuff to have a more survicable setup were bits are easy to get, I try to keep it as a set. For instance on yours ( v8 with single coil but 12 volt ) I'd look for a V8 (early Rover v8) coil and condensor, This way you can get the bits at your local factors. And the bits are compatable with one another.
Two important things to remember: With the points, a big spark at the points is NOT good, if you have a big spark at the points the condensor is buggered. Of course on your car seeing the points to check this is going to be really dificult, May be doable from underneath. And with originaly 6 volt ignitions (especialy Early Ford v8) use a coil with an external ballast resistor. This is due to the basic desighn of the caps and rotors, they simply do not last long with 12 volt ignition unballasted. There is not enough gap twix the lead terminals and stuff, and full 12 volt set up will jump the gaps and cause carbon tracking and shorts and all sorts of problems. They were originaly desighned to cope with approximatly 3 volts, ( 6 volt then a ballast resistor). I Know you have a ballast resistor, I just put this in for anybody else that maybe woundering.
Let us know what happens.
Martin.

Were have those santa heads come from?
 

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I had a similar problem with my ignition on a 59AB Flathead.
I had a dual point distributor and broke down a number of times. No warning at all in some cases.
A quick change of the condensor and it would fire right up.
As I understood the problem, the dwell was to long and this overheated the condensor, breaking down the insulation and it died.
The points setting seems to be oh so important even though the setup seems basic.

It may also be the case that the coil you have is unsuitable for use with a ballast resistor.
 

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I had similar problem with my 289 Ford V8 (obviously not a flattie! ) in my case the coil was wired wrong and getting a full 12v whilst running causing it to over heat, so car would just die after 30 mins or so, leave it to cool and off she went again. I think that was something to do with the ballast resistor and the way it was wired.
 

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Discussion Starter · #10 ·
The 12v ignition supply runs through the balast, to the coil (+ side), then from the coil (- side) to the condesor/distributor.

It doesn't have a direct 12v from cranking to the coil, always starts well though and runs really smooth, right up until turning itself off!

Will try a new condensor, I think the coil was listed for a landrover v8 for use with balast, so could try a matching condensor?

Will re-gap and clean the points too. Job for the weekend I think :)
 

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One thing to bear in mind with condensers is that they are a minefield in the classic car world at present due to quality. Many reports of failures and I've suffered it myself. You are best of with a nos condenser if you can get one.
 

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Hi change the points and condensor, if that dosnt wotk, when it fails ..check for a spark at the points?, if its lost it try looking at the (-) feed to the points/condensor, some-times these break down under load?
You could try by-passin it with another piece of wire from coil?
(same with ignition feed to coil if this dont work)
hope this helps
 

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Discussion Starter · #13 ·
Just picked up a couple of old stock condensors from my local car parts place, so gonna have a play this weekend.

Gonna go out with some extra tools and a multimeter so when it goes I can try and sus out whats up :)

Always hard tracing an intermittent fault, never bloody breaks down when you want it too......
 
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