Club126UK
Fiat 126 Chat => Fiat 126 Mechanical Problem Solving => Topic started by: michaelodonnell500 on March 28, 2017, 10:14:29 PM
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I was looking for a twin spark coil last week and the prices are a bit steep.
Other twin spark coils are available and they are still cheep so I thought I'd test one out to see if it works.
I bought one of these from eBay as they are very common and low cost. Better quality ones are available.
(https://uploads.tapatalk-cdn.com/20170328/5aa30fd7393312244d65c03a376721a2.jpg)
This has a plastic connector rather than 2 male spade connectors so I will need an adapter in the long run.
I tested it and it worked. Car started fine and ticked over as normal.
I will need to modify the bracket to bolt it in place. It's not a straight swap, but it is a low cost alternative and if you ever got stuck at the side of the road you could pick this up from eurocarparts and hold it in place with a few cable ties!
I've started making a bracket by removing the bracket from the old one:
(https://uploads.tapatalk-cdn.com/20170328/296a9eafedd19855082547720336645a.jpg)
(https://uploads.tapatalk-cdn.com/20170328/46768185ff7aac6ced95bf36553c5375.jpg)
(https://uploads.tapatalk-cdn.com/20170328/8854c29f91aa4a158e6a18c9f8a86f59.jpg)
I'll post an update once I've modified the bracket and done a few miles on it.
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Nice one Michael :)
After burning out two brand new £45 twin spark coilsas many weeks last year I got straight on ebay and got one of these for £9.28 .
I then remembered that in a lot of parts I bought last week there is a 126EL ignition set up. Guess what it uses that same coil pack. Also has the connector but sadly the two wires have been cut with only about 6mm left but I will be able to solder onto them.
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Hi!
In case someone is replacing the single coil to double, do not forget to use an external resistor. The models with the double coil power it trough a sky blue cable of 1.7 Om resistance, if I remember well.
Best,
Deyan
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Nice one :good:
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I've welded up the bracket to hold the coil so the cinq/panda coil now use the 126/500 bracket.
This coil measures 0.7ohm which is a bit low. I've read a number of different manufacturers websites which all, irritatingly have different opinions as they are written for different reasons.
Firstly.
Aftermarket distributor manufacturers require the coil to be at least 1.4ohms to prevent damaging the points. So I have bought a 1 ohm ceramic resistor to bring my coil up to 1.7ohms.
Secondly
Ballast resistor. I don't believe they are needed on a 12v coil. I have read that they were required on 9v coils. The extra current available upon starting allows a stronger spark while the starter is cranking and during colder months. Once the ballast has warmed up the resistance increases allowing the 9v to run in a 12v circuit. This is not the case for 12v coils because they cannot draw more current than they can handle in a 12v circuit.
I haven't used a ballast resistor in the 5 or so years my twin spark coil was fitted. The coil is now dead because I left the ignition on for 2 hours. I would recommend doing that, it creates a lot of smoke and it stinks!
I will test this new coil with and without a ballast resistor to compare results.(https://uploads.tapatalk-cdn.com/20170409/b504d5b375d8b9593e8909972663c947.jpg)(https://uploads.tapatalk-cdn.com/20170409/31688f4d12314be3917a60bf0c3ab7fd.jpg)(https://uploads.tapatalk-cdn.com/20170409/5afe895d76b8c70cfe20070ab3153a6d.jpg)
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Here is the 1 ohm resistor I boughtalong with a few leads I made up to bridge between the new coil and the existing wiring.
(https://uploads.tapatalk-cdn.com/20170420/6a1edd1d6e5a099ac3a61b018c80523d.jpg)
I'll make some better wiring up soon, this was just to allow for a simple test.
The lead on the right connects via the resistor to the ignition. The lead on the left connects to the distributor.
I took it out for a spin tonight and it ran fine. So far so good. I'll be using it from now on so I can update with some progress.
Once I've made up a connector lead I'll draw up some instructions on how to make a connector adapter to fit this coil without modifying the wiring loom.
(https://uploads.tapatalk-cdn.com/20170420/e6997779ec9d565e477e302dacc96d86.jpg)
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Here is the 1 ohm resistor I boughtalong with a few leads I made up to bridge between the new coil and the existing wiring.
(https://uploads.tapatalk-cdn.com/20170420/6a1edd1d6e5a099ac3a61b018c80523d.jpg)
I'll make some better wiring up soon, this was just to allow for a simple test.
The lead on the right connects via the resistor to the ignition. The lead on the left connects to the distributor.
I took it out for a spin tonight and it ran fine. So far so good. I'll be using it from now on so I can update with some progress.
Once I've made up a connector lead I'll draw up some instructions on how to make a connector adapter to fit this coil without modifying the wiring loom.
(https://uploads.tapatalk-cdn.com/20170420/e6997779ec9d565e477e302dacc96d86.jpg)
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Well that didn't last long! I've had 30 miles or so out of the new setup before it died on me.
The 1 ohm ceramic resistor failed which then caused the points to arc with the excess current going through them. The condenser may have failed too but I haven't tested it I just swapped it for a known good one.
I filed the points back, set the gap, redone the timing then put it all back together.
This time i have fitted a ballast resistor. The last resistor may not have been rated for the current that was being drawn through it.
On the plus side the coil survived the battle!
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Ahh that's ashame. Could it have been a dodgy resistor?
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It may have been. I'll check the specifications first.
I might try and replicate it on the bench so I can test it off the car. Redoing the points at the side.of the road is a nuisance I'd rather avoid!
I've been out for a few small drives with the ballast resistor and it seems to be working OK.
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I might try and replicate it on the bench & I've been out for a few small drives with the ballast resistor and it seems to be working OK.
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Good to hear that you two are getting along OK ;D
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I might try and replicate it on the bench & I've been out for a few small drives with the ballast resistor and it seems to be working OK.
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Good to hear that you two are getting along OK ;D
It's been a rocky relationship but we're working through it.
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Its a good trial I've often looked at these newer style coils and wondered if they would work on the older cars. Just out of interest what could potentially happen if you didn't use the resistor?
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once the resistor blew I was running it without a resistor! It allowed too much current through the points which caused them to arc and stop working. It may have killed the condensor too but I've not tested it yet. I'm not sure when the resistor blew so I'm not sure how long it was working without one.
the modern coils I have measured are all below 1 ohm.
Anything below 1.4 ohm will damage the points unless you add an appropriate resistor or add contact-less points (Accu-spark etc.)
I'll keep going with this and should be able to put together a conversion kit once I've ironed out all of the issues!
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once the resistor blew I was running it without a resistor!
Not quite sure I understand this - if the resistor blew, as in vaporised hence infinite resistance, in effect it acted as a fuse and that should have stopped the igntion completely. If the car kept running, presumably the resistor must have short-circuited to zero resistance?
You've probably seen these items already, but if it might be of any help, there is info on what resistance values to look for and the wiring for a standard set-up:
First a quick explanation of how a ballast system works
When a car is first started, the oil is thick and the engine is cold and hard to turn, so the starter will draw a large amount of current. Whilst cranking, you may notice the lights dim as the engine turns, this also means that the coil is robbed of current which in turn causes a reduced spark that will make the car hard to start. Often you will find the car starts at the very moment you let go of the key as this is the point it full voltage returns.
To overcome this the ballast ignition was developed. The car is fitted with a coil that runs on a reduced voltage. The coil is then fed through a ballast resistor or wire that reduces the current to the correct voltage for the coil.
Now the clever bit. When the engine is cranking the starter solenoid feeds the coil directly with 12 volts, bypassing the resistor. Although the car is cranking and all the voltage is reduced throughout the electrical system, the coil is receiving more volts than it requires which compensates for the voltage drop, thus giving a full spark.
How to test
Most people will tell you to test the feed for the coil. This tells you nothing - it will always show around 12 Volts because there is no load on the system, the resistor has nothing to resist ! ( unless the points are closed )
If there is no ballast resistor visible you may have a ballast wire inside the loom. To test for it proceed as follows:
Check voltage of battery with volt meter
Remove the wires from the negative side of the coil ( negative earth cars )
Connect a temporary wire from the negative terminal of the coil to earth
Turn ignition on ( nothing else switched on )
Now check the voltage on the coil, put red probe on + side of coil and the - probe to earth
If the reading is less than 80% of battery voltage there is portably a resistor in the system. If it is more than 80% you probably have a standard system
Remove the temporary wire and reconnect wires .
If your reading is less than 80% you should use a ballast coil , AccuSpark Blue
If you reading is more than 80% you should use a non ballast coil , AccuSpark Red
As a final note :
A standard 12 volt will only have a single 12 Volt feed to coil
A ballast system should have 2 feeds. One resisted feed and a second full 12 volt feed when the starter is engaged
Do I have the correct coil ? Testing your coil
To test coil set voltmeter to Ohms, test between -and + terminals. A reading of around 3 is a standard coil, a reading of around 1.5 is a ballast coil.
Removing Ballast resistor
What do do if you wish to remove the ballast system and go with a standard 12 Volt system ?
If you have a visible resistor you just need to remove the resistor and join all the wires.
If you have a ballast wire in the system proceed as follows:
Remove the 2 feeds into the coil and tape up
You can run a new wire from the coil to the back of the ignition key
You can also take a feed from the fuse box. This must be switched by the key and be on the live side not the fuse side. To test, it should still work with the fuse removed
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I`m running a standard bis twin coil on our air cooled with no resistor and haven`t had a problem so far.
Also on one of my later air cooled cars that was originally fitted with a twin coil there was a condenser connected to the coil as standard.
The 126Fan guys have it listed on their web site.
http://www.126fan.sk/eshop/index.php?main_page=product_info&cPath=16&products_id=112&language=en
And here is a picture I found on the internet. Ignore the rest of the stuff in that engine bay:)
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I`m running a standard bis twin coil on our air cooled with no resistor and haven`t had a problem so far.
I was running the same and I agree - no issues. my previous coil measured 1.7 ohms which ran fine without a ballast. Anything below 1.4 ohms is bad for the points. The ones I am playing with are approximately 1 ohm. the resistor I fitted was ok in theory, but it was not capable of dissipating enough heat to survive!
Also on one of my later air cooled cars that was originally fitted with a twin coil there was a condenser connected to the coil as standard.
Was that later car fitted with a nanoplex instead of a distributor? The condenser is to protect the contact points from Arcing so I just assumed that would have gone once the distributor was removed. It must be used to protect another part of the system from the coil, as if they were using it like a diode, they must have had plenty of them leftover once they scrapped the distributor
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Michael it was an 89 air cooled, so had a twin coil and a distributor. It had a standard condenser on the side of the dizzy and the second one wired to the coil.
On the other hand a bis doesn`t have such a thing fitted and I guess the coils are the same.
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The coil + ballast resistor has been in place for a week and seems to be working OK.
I have found connectors that fit the coil so I have made up a wiring adapter.
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Adapter(https://uploads.tapatalk-cdn.com/20170504/2359c2dd48ca26fdb63e215acec0c667.jpg)
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Adapter(https://uploads.tapatalk-cdn.com/20170504/2359c2dd48ca26fdb63e215acec0c667.jpg)
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I'm still running the twin spark coil and all is well. No failures since I added the ballast resistor. I've not been on any long runs but I'm using it about 50-60 miles per week.
I would be happy to recommend this system to anyone.
I will make up a few wiring and bracket adapters if anyone is interested in fitting a modern £10 twin spark coil to their fiat.
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Whas up folks!!
Been using this double coil for 6 months .. so far so good .. it comes with a huge capacitor
http://club126uk.co.uk/forum/index.php?action=dlattach;topic=9167.0;attach=9412
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My 126 Bis broke down last weekend at the Alexandra Palace intersection. There were a lot of good Samaritans about who helped me push the car to safety. Called the AA, but they couldn't fix it. They diagnosed the fault to be a defective coil (insufficient current). They were kind enough to tow the car home, and the following day to the garage. Proeitti had one in stock for a very steep £65 (excl VAT)! :-
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I have one NOS if you're interested, a lot less than £65. Around £45 plus shipping iirc. PM me if you want an exact price.
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Search for "4439396" on eBay and they go for £33 with free shipping
or there's a guy on the Facebook group selling one for £20
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The one I'm using cost £10 delivered. (New.)
Also available from Eurocarparts for £30 which is very handy if you don't carry a spare.
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Great cheap conversion, but I have some questions.
1. Can you maybe post link where could find connector that fit with this coil?
2. Did you add 1.0 Ohm or 1.5 Ohm ballast resistor?
3. In one of your post you mention
Anything below 1.4 ohm will damage the points unless you add an appropriate resistor or add contact-less points (Accu-spark etc.)
but here (http://powerspark.co.uk/k35-powerspark-electronic-ignition-kit-for-magneti-marelli-2-cyl-distributor/) it says
To be used with a coil resistance above 1.5 ohms only
so it's need to add ballast resistor anyway?
Thank you for your help!
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1. Can you maybe post link where could find connector that fit with this coil?
Ebay.
2. Did you add 1.0 Ohm or 1.5 Ohm ballast resistor?
I used a 1 Ohm ballast resistor . The coil is already 0.7 Ohms = 1.7 Ohms total.
A 1.5 Ohm ballast + 0.7Ohm ballast = 2.2 Ohms. No advantage, but excess heat may cause extra wear.
3.
To be used with a coil resistance above 1.5 ohms only
so it's need to add ballast resistor anyway?[/i]
I had not bought an Accu spark kit when I wrote that part and I should have updated it.
The system needs a minimum of 1.4 Ohms whether using points or hall effect.