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1969M1 - I will check this more carefully. I am fortunate enough to have an 'old school' Allen (Same as Crypton) engine scope. I will have to use it to check this out.
I would have thought that a 12v coil on the reduced volt wire would not produce a big enough spark to avoid mis-fires.
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I don't recall exactly, but I think they run at something like 9V. GM's and Mopar's all used ballast resistors instead of a resistor wire. Its been a long time but this is what I recall: The slightest thing goes wrong and misfires occur. I.E. reduced dwell from points wear, plug wire with slightly too much resistance, a spark plug fouls a little and the ignition usually cannot clean it. Obviously, the higher CR engines were more prone to misfires. In stock form, these were not very good ignition systems. I remember as these stock distributors wear, when the vacuum advance would move the breaker plate the dwell would decrease a little and misfires would occur. So, it was common to run without the vacuum advance. During crank, the resistor wire is bypassed for more ignition power.
I am only familiar with the Sun automotive oscilloscopes. When I was working as a mechanic, only a few car models had distributorless ignition systems so we still used an oscilloscope to help diagnose drivability issues.
Best Regards,
Mike
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'69M1 - The unit I have is same spec/function as the Crypton and Sun units. Great for early stuff and interesting on the later cars.
I'm loking at getting a decommissioned unit to convert to a 'shop fridge. I know where it is, just got to haggle about the price!
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I managed to bridge one of the wires so it works perfect now
Regards Rob
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Robsweeden, that's great. Now you know the choke is connected correctly and can move on to something else.
Best Regards,
Mike