I am restoring a 73 challenger with a 340 engine and 6-pak carburation. I have replaced the voltage regulator, the ECU and have the proper gap for the distributor reluctor. The plugs and plug wires and the resistor are new. When cranking all of the cylinders appear to fire, (individual header pipes get warm), and when I let off of the starter, it dies. When the starter is cranking, there is about 9.5 volts to the coil. At times it will backfire up the center carburator. If you ever want to see the neighbors kids eyes get really big, let them see that! Any ideas and thanks much!

 

Are you sure the polarity to the coil is wired correctly? I remember having a similar problem on my 73 340 and that was the problem. Had spark, but not enough to keep it running. It was over 20 years ago, so my memory is a bit vague but it's worth checking out. You may want to post something on http://www.cuda-challenger.comThere are a lot of tech savy members and all they focus on is the old stuff. Plus they love having new guys get on-line.

 

Thanks for the info. I have checked the wires to the coil (which is new) and the wires to the distributor, and they are wired correctly according to the factory service manual I have. However, I have seen a few posts indicating that sometimes the wires to the distributor are switched. But before I run around switching wires I will pull the timing chain cover and verify the setting. Thanks for everything.

 

Ballast resistor?

 

Thanks for the help guys. Last night after reading the forums, I moved the spark plug wires 1 position counter clockwise on the distributor and it fired right up.