Clois,
I may be way off the wall with this as I haven't used an MSD setup for a long time. But I had a similiar problem with one of my Cobras running the Jacobs Pro Street. If the MSD has an easy way like the Jacobs to convert back to running off just the distributor and taking the computer out of the euation, I would try that first and if you have a remote starter button that you can use from under the hood try it. When I took the computer out and just ran from the normal coil, distributor setup mine would start. So after much checking I found that the trigger lead from the distributor to the Jacobs unit had came loose inside the wire loom where it was in a connector. AfterI replaced the connector I have never had another problem. The fact that the engine spins over from the switch would take that mostly out of the equation for me and also the fact that it ran when you got it started. Rick's suggestion for testing the MSD unit is a great idea but just takes longer than the way I did the Jacobs. With the Jacobs set up I can do it in about 20 seconds. But maybe the MSD doesn't have that means to do it. Good luck. By the way I am using a magnetic type distributor also.
ron
