Hi, I have a 1973 Dodge Challenger with rebuilt 383 4bbl. With the key in start position the engine “starts” but then immediately dies when I let the key off to run position. Has spark (did spark test and actually put in new plugs) and fuel going into carb. Tried spraying in carb cleaner while trying to start but no luck. Just got flames eventually!! Battery is new and ignition switch was recently changed.
I did try attaching a jumper wire from the + battery post to the + side of coil and it started and ran. Had it in for less than a minute but thought that meant is was the ballast resistor. Changed that but still the same problem. Thinking then it was maybe some weird wiring issue, I ended up just swapping out the engine wiring harness but that still didn’t work.
I think I’ve exhausted all YouTube searches so any suggestions would be greatly appreciated!!