[Skip Newsom]

I bought a stock 72 911T Targa last August and have been working to bring it back to life and looks.

After getting it running in September and driving a couple hundred miles, it suddenly started missing severely and I limped home with it. After that I did as much trouble shooting as possible, cleaned ground wires, fuses, fuse block connections, and then it would not fire at all. I replaced the Bosch MSD unit(even though it whistled) and coil with a Permatune box and new Bosch coil... It started and ran good. I put about three thousand miles on with no problems.
(I had already replaced the spark plug wires, points, dist cap and plugs)

A few weeks ago I decided to see if the original Bosch unit would work, hooked it up and it ran even better!
I drove around a couple of days with a grin on my face and took it to my first car show. It started right up after the show was over, ran for about 45 seconds and died. No hint of spark. I had put the Permatune unit in the glove box and had some tools along, so I swapped it out.. it ran fine again.

So a couple more hundred happy miles go by, I'm sitting behind a school bus idling and yep, it dies again and refuses to start... aaarrrrgggg!

As luck would have it gravity and a short tow got me home. I start trouble shooting again using the Haynes manual... no obvious problems, but it won't start. I change back to the old Bosch unit, no fire, change back to the old coil too... it runs again!!!

I don't trust it now and am not sure what else could be causing all this fun.

Any suggestions?