A couple of months ago I wrote concerning ignition failure on my 62 Valiant. I determined it was the MSD 6AL that had failed so I put in my back up unit and it also failed after about 3 hours of use. I sent both boxes back to MSD and they repaired them for a very reasonable price. I also asked them to assess why they had failed and they said it was due to a voltage surge or spike. They said it was probably not anything you would see on a voltmeter, could be the result of a poor ground. Obviously I don't want this to happen again but I am somewhat at a loss as how to prevent it. These are the steps I have taken since the second failure. 1. Rebuilt the ignition switch plug, some voltage was bleeding to the accessory circuit with the key off. 2. Separated all hot wires from accessory feed wires and enclosed them in separate insulating sleeves. 3. Changed alternator and voltage regulator. 4. Increased the size of the wire to ground that serves the MSD and other accessories. Today it ran on the new MSD. Can you think of other things that might cause such a problem and how to fix it?

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If you didn't drive it there, it's not a street car.

Add a big capacitor to the power line supply to the MSD to absorb any voltage spikes.

At least 10,000 MFD @ 25 volts


If you have an industrial liquidator near you, you can get it for a couple of dollars.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Looking through various boards, I have seen many complaints about MSD systems. That said, they repaired yours and didn't leave you hanging, so that sounds promising.

The capacitor sounds like a great idea to suppress spikes. Though, I would think after much experience over the years, MSD would build in a surge protection circuit and call it a day. After all, they advertise their wares for mid-century vehicles, they must know those systems are prone to voltage spikes and such.

b

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https://tinyurl.com/yynpj4v2

Switch to HEI and have ignition that's at least as good and a hell of a lot less expensive and more reliable.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.