Yikes, had the '70 Mach 1 towed home today!

[machoneman]

My 351W '70 was cruising down the road in suburban Chicago today (hey it was a great day!) when all of a sudden, the engine died. Had to get it towed home (booh! a first in 18 years since I  first got her running) and can see the ditzy gear and roll pin is fine, it cranks fine, lotsa gas but no sparkee!

Had my ancient (yes ancient as in 1977!) MSD 7 box off an old dragster that has been on the car since 1996 but had MSD fixed it up a few years ago as it quit one day in the garage.

This time, I suspect either a.) my Mallory Unilite module (had the same one for 18 years w/o any issues) or b.) the MSD box. 

Any discriminate views on how to tell which it is?

[jayb]

That sucks.  My Galaxie just blew out a couple of flywheel teeth over the weekend, but it had the decency to not start in the garage.  Of course, I'd rather change a distributor or MSD than a flywheel 

I don't know of a good way to distinguish between the MSD and the Unilite as the source of trouble, without swapping one or the other.  Do you have a points distributor you can pop in there and see if it works?  Better yet, do you have an FE you can pop in there and see if it works?

[FirstEliminator]

   I believe there is a way to check the MSD box. Someone the other day was talking about how they checked their MSD by applying power then removing to power to collapse the field in the coil. Or touching two of the MSD wires together. I don't remember which one, but  I think they mentioned it was in an MSD manual---which would be online. Sorry my post is vague.

  Mark

[machoneman]

Hah! No FE sitting around Jay. Yes, it's mighty decent when a car has it's trouble only in the driveway or garage. I'll bypass the MSD box today and see if it fires up.

That sucks.  My Galaxie just blew out a couple of flywheel teeth over the weekend, but it had the decency to not start in the garage.  Of course, I'd rather change a distributor or MSD than a flywheel 

I don't know of a good way to distinguish between the MSD and the Unilite as the source of trouble, without swapping one or the other.  Do you have a points distributor you can pop in there and see if it works?  Better yet, do you have an FE you can pop in there and see if it works?

[My427stang]

If it is the Unilite, the Accel points eliminator kits are the same and much cheaper.  39.95

[machoneman]

Update: I by-passed the MSD 7A box and the engine fired right up.  Happy it wasn't a sheared roll pin nor a shredded flywheel ring gear    but still.....

The box was rebuilt by MSD in July of 2010 as it shorted out that summer. Only took about 10 days and $110 to turn it around. But, seeing as how it survived for 33 years (on two cars over time) and had just been been re-done 1 month short of two years ago (35 years of ownership)  it is a tad disappointing it failed again   

Maybe I'm too picky! Time to get a more streetable -5 box.

[machoneman]

Update: got the MSD 6 box in from Summit last week, wired her in and it fired right up. Kinda' sorry now I spend the $$$ a few years ago to re-do my old 7A box. Like the unified wiring port and easy-to-set rpm limiter.