I have a '70 Mustang Coupe with a 351C and Tremec 5 speed. The problem that I am having is that the car starts and runs fine, with the exception that it will die unexpectedly. It will restart normally and may run 5 seconds to 20 miles. Is this related to the ignition switch on the column. I replaced the ignition with an MSD 8350 and Blaster coil, which seem to be operating fine.

 

sounds electrical...the ignition system is a lot more complex than the coil but you might be on to something suspecting the ignition switch.

Next time it dies dont touch anything, pop the hood and see if you've got power to the coil.

Is the car running points or it it an electronic ignition like the MSD A6.

-Gun

 

With the volt meter on the positive side of the coil, the voltage of 6.95-7.05vdc drops to basically nothing when it dies. Electronic 8350 MSD with the blaster coil.

 

I had an a6 fail like that.

There is a self-test you can do with the a6 box to determine if its the box or something else. Find the manual for the 8350 and see if there is something similar.

 

Hi,
I would contact MSDs tech and ask what the coil voltage should be in the "run" ckt. Their wiring schematic appears to suggest a full 12Vs to the coil. If so, where did you pick up your power to the coil? You may be running through the resistor lead which is in place to reduce voltage( numbers you mentioned) when running "points" ignition.
I would verify this through MSD.

 

Thanks, may have to do that. It started dying once I started running electronic ignition. The HEI unit I had on it did the same thing. I may have to install a 6AL box to remedy this problem, if it is not the ignition switch.

 

Hi,
Although the 6AL boxes are nice to have and optimize the whole ignition system, I don't think it's going to solve the issue. If it does, it's only because the box requires a dedicated 12V supply. It's the 12V supply to your current coil that needs to be checked. as I mentioned previously. Don't pull the trigger until you do the research.
Good Luck