new engine wont stay running

[guys71cuda]

it fires right up but as soon as i let off the key she dies. what could be causing this?

[Moparal]

Ignition switch or ballist resistor

[MEK-Dangerfield]

The ballast resistor is a cheap fix, but what ignition system are you running? Stock or MSD or something else?

[guys71cuda]

the ballast resistor was right before pulling the engine in august. its cheap worth a try i guess. i have the stock ignition system.

[Bullitt-]

With a meter or a test light you can check for power to & through the ballast

[Tonefiend]

I had the exact same problem a few days ago.  Turns out it was a loose wire at the ballast resistor. 

[guys71cuda]

made sure the wire connections to the resistor were on the whole way. no luck. replaced the ballast resistor. still no luck. what else should i check for. it will keep running with key turned but dies the second i release the key from the start postion. .

[Bullitt-]

There's all the wiring & connectors from the steering column through the firewall bulkhead, any broken wire or bad connection of the run circuit will cause this, & finally the ignition switch itself (lets hope not).

[guys71cuda]

how would i checkthat  the ignition switch is working properly ?

[73EStroker]

Checkout what Bullitt says. A little background is that there are two wires that come from the ignition switch out to the ballast resistor/coil. One is 12V to the resistor with the ignition in the 'on' position. The other is 12V direct to the coil (ie. bypasses the ballast resistor) in the 'start' position only. Your engine is running on this bypass circuit only. Trace the wires back from the ballast resistor to the firewall. With the wires identified place the ignition switch just in the 'on' position then look for 12V (with a meter or test bulb) at the bulkhead connector for the wire that goes up to and through the resistor. I think that is the dark blue wire. If no voltage at the bulkhead then go inside the cabin and trace back to the ignition switch via the plug in connector on the steering column. ( times out of 10 it is a bad connection at the bulkhead. There are new terminals available for the bulkhead which I recommend you change out. I replaced all of my connectors (male and female) at the bulkhead during my resto and no problems so far. Also did the light relay wiring to take the large loads away from the bulkhead and the light switch.
I know electrical is what most people hate doing but my motto is if you are down there trying to fix it get a wiring diagram, study it for a while then do it right and do it once. Hope this was useful.   

[Chryco Psycho]

I have seen the dist pick up coil fail as well , the engine will stat & after a minute or so the coil will heat up & quit