Hello everyone,
I literally joined this forum just so I could get a consensus on this problem. I have a 1973 dodge power wagon with a 360ci/ 5.9 litre engine that has been sitting for 6 years. Since this whole covid thing happened my father and I finally had the opportunity to get it running. the engine was seized up due to it sitting for so long, but we were able to free it, and start it up. When we take it on the road however it runs like a champ for a while, then it begins to backfire like it is missing on one cylinder, then it dies out completely. this has happened four times already. I have rebuilt the internal portions of the distributer, I have replaced the coil, I have replaced the spark plugs, and I have replaced the ballast resistor that sits on the drivers side wheel well. I honestly don't know what to do, it seems like a spark issue because it is getting fuel. The carburetor needs a rebuild but it is still functional. The only thing I haven replaced was the spark plug wires because they were brand new when it started sitting, and this would not explain why it dies all at once. I have absolutely no idea where to go from here, I am all ears for ANY ideas or solutions.

 

It may be vapor lock, What is the temp gauge saying? Ambient temp outside? Also these truck had many issues with the wiring(amp gauge and bulkhead connector) you may want to look into.

http://www.madelectrical.com/electri...p-gauges.shtml

 

If you're positive the fuel is getting there and enough of it, try swapping your brain box for the ignition. I'm assuming when this happens, you have the hood shut and not open or removed. I'm thinking you have a heat soak problem with the controller for the ignition. I've only seen this twice but both times, it acted like you described. It will start and run fine for a bit. Then start missing and stuttering and then shut off. It won't restart until the controller cools down. There is probably a cracked solder joint somewhere that the crack expands when it gets warm. Considering the age, (47 years old) it may be bad. Who knows, that might be why it was parked to begin with. I don't know how much they run now but swap another controller in and see what happens. Do NOT try to put a lean burn unit on there, stay with the little box with the odd shaped plug that is on all Mopars with electronic ignition.