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Thanks for the reply quadrifolio. I guess there may have been a bit of presumed knowledge i'm lacking. I'll give it another crack shortly. Out of curiosity does it matter which way you rotate the body to get the LED to light up? It's just that the instructions in the booklet differ slightly to those in the following link http://123.neortic.org/manualsPDF/123ALFA4RV.pdf
 

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Discussion Starter #202
First check to see if you have a spark. Insert a plug lead into the coil, bypassing the distributor, and spin the motor. If you have sparks then you have a timing or plug wire related problem or fouled plugs. If you have no sparks then you have a wiring problem or a defective distributor or coil.
 

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Either you´re not in compression stroke for cyl.1 (means your dizzy cap is pointing towards cy. 1 connector & lead, but your piston&valve hardware isn´t at TDC for cyl. 1 in compression stroke) or you´ve been setting up the green light in the wrong position turning on. Compared to a standard points dizzy that would mean the points are just closing and not just opening. Which would mean you have the spark timing wrong to fire up. Try to crank by somebody else anf while cranking turn the dizzy CCW about 10-20°. If you´ll notice the engine willing to start, you´ve set up the green light turning on in the wrong way.

As to check your wiring: Is the coil correctly wired ?
 

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Start with the obvious stuff: pull a lead to a plug and make sure that you are actually getting a spark. If you are, then we know the system is working and it's a matter of alignment. If not, then check your coil lead and then the coil wiring and then your rotor. I had some trouble with the rotor not being properly seated when I first installed mine.

On my car, with the Alfa logo in the grill representing 12 Noon, the rotor points to roughly 10 when piston #1 is at TDC. Make sure that things are tightened down enough that the distributor can't rotate out of position when you try to start the car.
 

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The first thing i did when i started was wire the new coil up to the old distributor and try it just to check the new coil was good. I took photos of the wiring on the coil and just copied it over . It started no problem with new coil and would run provided you gave it revs but refused to idle with the new coil, it would then stall and there'd be some noticeable smoke coming from the carbs. As i understand it there can be issues surrounding impedance of the coil so just assumed it was issue related to an old distributor being matched to a new coil and when the 123 was installed that would no longer be an issue.
 

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Discussion Starter #206
A coil of less than 1 ohm primary resistance will damage the 123. Someone posted about the failure happening immediately. Have you measured yours?
 

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I haven't measured the resistance of the coil. It's just a standard blue bosch coil and i assumed that as it was new there wouldn't be any issues with the resistance. I'll go and measure the resistance to make sure everything is okay though. Thanks for all the advice. I'll report back when i get around to giving it another go next weekend.
 

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Discussion Starter #208
A Bosch Blue coil will not damage the distributor, nor will it make the strongest spark. The Bosch Red coil has a primary resistance of 1.3 ohms which is about as low as you can find in the acceptable range. It will make stronger sparks than the Blue. Many of the high energy coils are around 0.7 ohm and they will damage the 123.
 

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123 Programable

Has anyone had experience with the 123 programable versions, ether the usb connection or the bluetooth version?
Thanks,
Mark
 

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Hi everyone

I wonder if it is normal that the distributor finger on my distributor (bluetooth version) moves with the distributor while you align it with the green LEDs. I can avoid that by pressing down the distributor a bit when turning it ccw. However once I stop pressing it down because it is aligned, I have to make sure I don't touch the finger anymore, otherwise it would change its position. I also encountered the situation where the LEDs were hidden by the aluminium disc completely...

The manual contains this instruction:
(also press the rotor in a CCW direction, to remove any free play in the drive)
Does anyone know if it is okay if the distributor finger can move during the alignment of the distributor with the green LEDs or if you even have to turn it ccw first before you start aligning the distributor?
 

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Got it fixed with the help of @Mound Dawg

I was confused whether it is ok that you can move the dizzie finger of the 123 by hand or not. It moved even though I aligned the key drive with the slot. I wasn't aware of the fact that it actually matters which way you slide in the dizzie because the key drive is off to one side. If you put it in the wrong way around (180° off) it might feel like it is in place although it is not. I guess this is common knowledge or even already discussed in this thread and I overlooked it...
 

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I wasn't aware of the fact that it actually matters which way you slide in the dizzie because the key drive is off to one side. If you put it in the wrong way around (180° off) it might feel like it is in place although it is not.

Ask me how I know this . . . :)
 

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ain't that the truth :wink2:

ok, I can't stand it, isn't anyone going to ask how I had a right hand drive Giulietta?
 

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Discussion Starter #219 (Edited)
123 with low resistance coils

One of the limitations of the 123 is that it must be mated to a coil of at least 1 ohm primary resistance which rules out the high energy coils such as the type that are used in Marelliplex. My solution was to interface an MSD6AL between the distributor and the coil but I have decided to change direction. I have concluded that multiple spark discharge is mainly hype to cover the fact that inductive ignition makes higher energy sparks than capacative except at high rpm. Capacative can make higher voltage sparks but the duration is much shorter and the total energy is less. Also and MSD adds complexity which adds failure modes and makes trouble shooting more difficult. I have removed my MSD6AL and I am currently running an MSD Balster coil with a ballast resistor but I want to eliminate the resistor and make full use of the coil. Yesterday I successfully bench tested a circuit using a GM HEI module triggered by a signal generator that simulates the output from the 123. The GM module requires that the input be isolated from the coil circuit and that is not the case with the 123 output so I used a miniature isolation transformer between the signal source and the GM module. It made good sparks over the full rpm range. I observed that the average current supplied by the GM module to the coil is rpm dependent. It is low at low rpm and it increases to a maximum of about 1.5 amps at 3000 rpm and then it slowly declines as rpm increases. The low current at low rpm is because the coil fully saturates between sparks and there is a "rest" time between the pulses. The gradually falling current above 3000 rpm must result in a reduction in spark energy but it is a gradual decline and is still good at 7000 rpm. I did the tests with a coil from a GTV6 and I will do it again with a different coil to see how it changes the current. I also noted that the coil current varied with the voltage of the trigger pulse and that surprised me. It needed a lower voltage when the isolation transformer was introduced as it distorted the square wave into a wave with sharp spikes.
The next step is to try it in the car and that has to wait until I build a heat sink for the GM module. I could buy one specifically for the module but I think that I can make one for a fraction of the price using standard heat sink extrusion.
 
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This promises to be an interesting project, Ed. Are you using a higher output GM style module? I installed an Accell GM module as recommended by RJ and have been very pleased with how it works in my MarelliPlex. I recall you mentioning that you'd had some module failures with a MarelliPlex. With that in mind I tossed the heat-sink grease supplied by Accell and, instead, used a computer CPU heat sink paste (Artic Silver I think). It's been working flawlessly for several thousand miles now.

My first experience with an MSD6A was aimed at using the milti-firing capability to, hopefully, better control the combustion event in a 10.5 compression 2 liter running on 91 octane gas (this was a long time ago). I'd read about Otto cycle engines having a 2300 rpm pre-ignition moment which I was experiencing. The experiment worked. The multi-firing MSD controlled the flame-front and the pinging completely disappeared even in high Texas summer. David Vizard commented in one of his books that the MSD would make more power when used in conjunction with open chamber heads. Changing from a standard MarelliPlex to one linked to an MSD made a seat-of-the-pants difference in my case. It'll be interesting seeing your experience going the other way. This is what makes the BB so much fun.
 
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