Coil could be hot and acting up?
Is your idle speed screw missing or misadjusted? This would cause it to not idle.
Check all your battery conections, and be sure you have good cables. I like 2/0 or even 3/0 for 6 volt systems.

Grigg


1951 GMC 250 in the Project Journals
1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-