Issue at idle with warm engine

[Voss]

Lately my Charger has developed an issue when sitting at idle with engine fully warmed. The problem first appeared at a cruise night a few weeks back. The car started to bog out at idle, and eventually died. No issues what so ever to start again. It did this like 10 times on 5 hours so needless to say I got to locate the issue and fix it.

Car is a 68 Charger with a 440, a Carter AVS 4429S carb, and a stock style points distributor. I also have the vapor separator and hard lines to the carb. Tank vent is fine and not clogged. After doing some more investigations I found that when the car starts to act up, I can always save it if I give a little gas. No bogs or issues what so ever when driving, it runs super strong. The issue is only at idle. It is especially sensitive if I go from Neutral to Drive and sits at low idle with the foot on the brakes. But it has happened that it acts up even when sitting in neutral. But it is ONLY when the car is fully warmed up (about 190F). Never when cold.

Yesterday I checked the timing, replaced the coil and ballast resistor (since I had these parts on the shelf), but still the same issue. One interesting thing is that I couldn't reproduce the issue when sitting at idle with the hood open. I had the car running for about one hour (while doing some cleaning of my garage), and it never stalled. But when I closed the hood the issue appeared like after 2 minutes. So SOMEHTING is affected by the heat which builds up in the engine compartment.

I hooked up my dwell meter and it reads stable 31 degrees. It charges good at about 14-13.5V at idle.

I do feel this might be ignition related so my next step is to replace the condenser, rotor and cap. They are all fairly new however (2 years). I have more or less ruled out a vapor lock since the car fires right up after it dies. I am thinking I might have a weak spark, maybe due to a failing condenser, or a crack in the rotor. Since at crank the ballast resistor is bypassed the coil will se a higher voltage than during normal run, so it might explain why it is easy to start again after it died.

Next thing to think about is of course carb and fuel issues, but since it runs super-strong I started in the ignition end. The carb is professionally rebuilt a few years back and has worked perfect. The thing I did replace last season was the distributor, bought a A1 Cardone unit. I have heard both good and bad things about them. But the dwell is stable at least and it has worked well up until now. Maybe I should mention the ignition is set at about 7.5 deg, and I run ported vacuum to the distributor.

I have to solve this, so the rotor, cap, condenser  and points is next in line... If that does not help I am starting to run out of ideas. Or at least I have to start thinking about if this is really a carb issue.

Any thoughts from someone who has experienced something similar?

[BDF]

I had a similar and VERY FRUSTRATING issue with my car. It would run perfect cold and cruising but when hot would die immediately when put into gear (like a kill switch!) and intermitently run crappy/stall at low speeds. To make a long story a little shorter someone had just taped up the wiring harness covering up a frayed coil lead.
When cold & "tight" the connection was fine so testing showed it ok. When car got hot it would sag & have bad connection. 
It took so long to find that in the process I found & remedied a multitude of other stupid things done to it and now it runs better than it ever did since my Dad had it "worked on".
I will ask VegasCharger to post a pic of the wire...

[Voss]

I had a similar and VERY FRUSTRATING issue with my car. It would run perfect cold and cruising but when hot would die immediately when put into gear (like a kill switch!) and intermitently run crappy/stall at low speeds. To make a long story a little shorter someone had just taped up the wiring harness covering up a frayed coil lead.
When cold & "tight" the connection was fine so testing showed it ok. When car got hot it would sag & have bad connection.  
It took so long to find that in the process I found & remedied a multitude of other stupid things done to it and now it runs better than it ever did since my Dad had it "worked on".
I will ask VegasCharger to post a pic of the wire...

That's interesting! I will hook up my multimeter to the coil + and also my dwell meter to the - and run with the hood closed. If there is a bad wire or connection I should be able to track it down. My main theory is that it is an ignition issue. At least I need to rule it out before digging into the carb. As I mentioned, I don't think it's a vapor lock since the car directly fires up after stalling. The feeling is best described as a "weak" idle. I had the air cleaner off and looked for evidence of flooding when it stalls but there is absolutely no signs of that... Will work more on it tomorrow and post an update.

[VegasCharger]

I will ask VegasCharger to post a pic of the wire...