I have a 68 Ford F100 short box with a mild built 390. I just got a MSD Pro-Billet distributor and MSD 6A box for it. I got spark out of the box and coil but it only cranks but doesn't start, any suggestions. Thanks

 

Are you getting spark at the plugs??? If so, what color is the spark (blue or yellow)? Is the rotor seated properly? Is the distributor in all the way? Is your timing correct? Oh, and I remember something about a ballast resistor??

Slik

 

Eric:

Definitely check to be sure you’re getting spark at the plugs, but be careful because the MSD 6A packs quite a punch. While you were adding the goodies, did you also include a hot aftermarket coil, like MSDs Blaster2? If you didn’t then you should. They provide a much hotter spark than the stock coil and, because they generate 40,000 volts, you need to gap your plugs in the .050” to .055” range.

In addition to the things mentioned by slik, if you can’t start it and your fuel delivery is OK, then also check to make sure your timing is close and make sure you wired the distributor cap properly. The rotor turns counter-clock wise. Use the firing order and the #1 spark wire as the starting point.

The MSD 6A doesn’t need a ballast resistor. The 6A box gets its power directly from the battery via the heavy red wire. The wire that comes from the ignition switch and usually energizes the coil now goes to the 6A box and tells it when the key is turned on. The 6A box also has two wires that go to both sides of the coil to energize it.

Within the past 18 months I’ve installed MSD 6A boxes into my ’68 Mustang with a 289, my ’84 Bronco with a 302 and my latest project, a ’71 F-350 with a 400M. It dramatically improved the performance in each one and also makes them much easier to start, both hot and cold.

Good Luck

Bruce

 

make sure you have real good conections on all your wires.msd recomends you solder all conections.this could be the problem.

 

 

Why is it that everyone installs MSD-6A's? I personally am putting a MSD-6T in my 78 F150, becuase I figured the extra abuse I'll be putting the truck through might wreak havok on a standard 6A..

Any thoughts on that? Or did I just waste an extra $50 for nothing?
I also bought a high-vibration MSD coil....
Thanks,
Matt

 

Bruce,
Did the better ignition improve the mileage at all? I read a post a while back that the FE engines could be improved "with a few modifications" and wondered if that is one of them. Headers, I assume, maybe a better intake manifold/carb.

 

About the only thing that will make a noticeable improvement in the old Ford iron is rear gear changes. All others are slight at best. When those monsters were built, there was no concern for better mpg.

JRW