Hi Guys,
To start I have an MSD 6A box, SS Blaster coil and an MSD distributor suppling spark to my 406. I'm driving the car today and all of a sudden the motor dies. Not out of gas put put but off like I turned the key off. I coasted to the side of the road, tried to restart and nothing. Popped the hood checked around for anything obvious. A couple of minutes later it fired right up and I went on my way. About 20 mins. later it did it again. I repeated the process but this time it took a little longer to finally start.
Any one have any experience with the MSD stuff or do you think the problem lies some where else. I was thinking fuel pump but I have a clear filter just before the carb and it was full and as I said before, it wasn't a run out of gas shut down it was an immediate turn the key off shut down. :dontknow:
Thanks for any thoughts, Ang.

Most likely a loose connection or even a short somewhere. Not the easiest problem to locate . Some causes other than your connections could include worn out ignition switch { yea, it's a connector too inside}, unprotected tach wire grounding out somewhere. These 2 items can be very random on when they occur, personally had both in work truck.
Other possible causes include coil overheating. Actual msd box not most likely cause. Break in pickup coil wire, or other wires.
Recheck all connectors that could be related in any way, wires at starter etc.
Happy hunting

I'm running the same coil and box never had a problem, I had a loose connection on my HEI dist on another motor that did that to me 3 times before I found it. Made it home with a Zip tie!!!:nanawrench:
It sounds like you've got something grounding out.:dontknow:
Donny

The 6AL draws it's power directly from the battery, only the signal to turn it off and on comes from the ignition switch.I had a problem similar to yours in my 64. It turned out to be a bad circuit between the switch and the box.
I've had many MSD systems on race machines. Several times I returned them to the company for failures. They are very good at repairing and returning and very reasonably.Their testing cycle takes a couple of weeks. Try bypassing the box and try to replicate the problem.Very critical to make sure the ground strap to the box is 100% tight and clean.

Thanks for the input guys,
Today I started the Elkie in the drive way and while it was running I went under the hood, moved and shook around every wire going to and from the box, coil and the distributor in hopes to make the car stall... to no avail. Also while it was running from in the car I jiggled the key/ignition switch and still no stall. I went upstairs and got a beer after that. Then I traced every wire from the box and found a spice on the main power wire to the box that had been arking and loose in it's butt connector so I replaced that wire from the box to the battery with a nice new piece of 10 ga.. I then fabricated new ground straps out of 6ga copper from the battery to the alternator and then from the alt. to the engine block. When I started the car it ran fine and I could also see, acording to the volt gauge that the alternator seemed stronger than it was with head lights, blower, wipers and any thing else I could turn on.
I'm happy with the results of the day and I've got my fingers crossed that the arking power wire and the poor gound was the problem, but we'll see what happens.
Thanks again, Ang.

Sounds like hopefully you nailed the problem. Sometimes the best advice you can get is----- to help you think to find it yourself. Sounds like lockjaw was the closest.:beer:

Man, this sounds so familiar with a problem that I am dealing with. Mine did the exact same thing. Bypassed the MSD 6AL box and it fires right up. Does a bad MSD box work intermittently or does it just simply work or not work?

Butt connectors are a car owners worst enemy! Solder and heat shrink all the way.

X2 on the butt connectors. I only use the Amp brand, with their luggers to crimp them. Not for everybody though, since new luggers are over 650 bucks now. Never use butts for any current carrying wiring though. And solder & shrink tubing are cheap compared the best wire terminals, like AMP butt connectors at over $.60 each.

Yeh,
The guy that put the system in used them but when I found them out came the soldering gun and the heat shrink. So far so good. As we all know tracing an intermittent problem especially an electrical one can be a real PITA, I've got my fingers crossed.

Bigbranz, I don't know about the box but one thing to check if and when the car cuts out is the coil, feel it when the car dies or after driving for a while it will be warm but not hot. If its hot to the touch it could be on the way out.
Thanks again Guys, Ang.

Dang, my old electrical system is full o butt connectors, and splices and old dead wires, that might explin the unusual volatage drop when I put on the turn signal, ticks back and forth between 12 and 14 volts everytime the signal engages. I hate tracing wires especially in a 40+ year old car with original wiring. But I hate taking the bus even more.

My 2 cents worth. Butt connectors are fine if they are crimped with the proper crimp tool. It should have a half moon on one side and a point on the other half, the point should be on the solid side of the metal part and the half moon on the side with the split in it. Don

x2 on the right tool,, one better is the butt conectors without the split,, the solid ones..:texas:

The connectors from the Amp brand also have a metal sleeve in them to grab the insulation on the wire, so all the tension isn't just on the wire itself.
Nothing worse than cheap connectors, put on with a cheap tool....