I like to have all the mechanical advance in by 3000 RPM for both my drag racing and street and strip cars

I bring it in as fast as the motor will tolerate without detonation, 15-1800 RPM if possible

Believe it or don't but I just went through the exact problem with My 472 Hemi I changed carb..new fuel filter..new high flow fuel pump...cleaned all the paint off the orange box and fender to get a better ground..none fixed it. A friend told Me to check the alternator as He said it might not be putting out enough at low rpm. I checked the alt and it was good but noticed the belt was not as tight as it should be. I tightened the belt and have no stalling at idle any more. And that's the truth.

I am glad you found a solution But electrically, it does not make sense. If the alternator output was low, the battery should have supplied adequate current/ voltage to compensate for the low alternator output. The exception being the battery is very weak or there is a problem elsewhere in the circuit. In that case the Alternator could back feed the circuit to mask the root cause

Batteries store current, they cannot make it after they are activated the first time
They can recover when in decent shape, but they cannot recharge themselves beyond their float voltage

I worked this issue along with an established Mopar Guy of over 50 years,( his time of experience, not how long I worked the problem,lol) even He said He learns something every day. The car would not stall when warming up...take it out on the road immediately after startup and it ran normal. Once warmed up at operating temp, it would idle at a light for a short time and stall if too long waiting. IF put in neutral and run at high idle,1300rpm, it would not stall. So after tightening the belt I "assume" it was slipping at low idle enough to drop voltage at the box. It would not stall when warming up as it had a higher idle speed while warming up. Makes sense or not, I have had the car out several times and it runs and idles great.

I’m all out for ideas, that’s why I’m here and will definitely check it out.

have you checked the gap between the pick up coil and reluctor tips As I recall the gap s/be ~ .006-8" and checked with a brass feeler gauge. The two should be parallel to each other as well with no chipping of the tips.
One could also try another pickup coil.
Might also check for excess play in the shaft.
I have also in the past run a small braided ground strap from the control box to the engine to make sure the box, egine and distributor are grounded to each other.
Really stupid question, Your distributor clamp is tight, Correct?

I’ll check “everything” you mentioned TJP

Check not only the belt but get the alt checked. On another note of craziness...At the mopar shop a mechanic was switching from mopar electronics to MSD. Car started for a second then shut off. (512 motor)..Car would crank but no start. All wiring/ground were correct. Solution was the diode in the alternator went bad. Replaced alternator and car runs fine. Also as a side note..runs 6.80's in 8th. Figure that.

Also...Chrome alternator pulley's, like mine, tend to slip a bit more than stock pulley's.

I just had a thought,
Hook up a temporary red light to the input side of the ballast which also feeds the control module. Place the light inside the car so it is clearly visible when the car dies. if the light goes out your part of the way there. If not go to the control module and check it's 12 V signal, then onto the coil. IF all of the above maintain power your remaining components are the coil itself or the signal between the distributor pickup coil and module or the module and the negative side of the coil. Keep us posted

Bobby, start it & with it running & hood open, jiggle the wires that connect to the ballast resistor. If you see a spark & the engine quits, you have a bad $3.00 ballast resistor. Went through this on my old '71 Hemi Charger - took two weeks to find the problem, & I found it by luck!

Terzmo, I believe we might have had the same problem. I did a few things to the car 2 weeks ago and no luck, yesterday I tightened up my alternator belt and test drove it today and it didn’t stall, I’m going to take it out tomorrow for another test drive to be sure, but I think we found my problem! Thank you, that’s why I posted my problem thinking someone might have had the same issues. Thanks again!

I’d like to thank everybody else for their input also, thanks guys! Hope this isn’t premature but I think it’s fixed.

Sorry i didn't see this earlier
I'll agree but still not understanding why the battery was not able to supply the needed current unless it was weak. I'm ASSuming we are only talking about a few amps to run an ignition system.
The car stalls because of a slipping alternator belt. But immediately after stalling, the battery has now has enough Current to engage the starter and power the ignition system until the alternator spins fast enough to replenish the battery? Doesn't make sense and sounds to me ?
Please feel free to educate me

The alternator regulator will make the alternator charge more when the engine first starts due to the drain on the battery from the starter turning the engine over and making it start, with the belt tight the alternator will put out over 12.75 VDC idling, it may only put out less than the minimum voltage the ECU has as it cut off voltage at idle with the motor warmed up with a loose belt
A quick check with a decent voltmeter will tell you if that is the case or not

The part I am having trouble with is why the battery which should be at ~ 12.4- 12.6 won't keep the car running, but will start it powering both the starter and ignition, during which time the static V will drop to 11 or so volts due to the amps drawn by the starter.
I am not disagreeing or wanting to start an peeing contest but rather understand how low alternator output at idle makes the motor die but start right back up with less available V and I from the battery than was available when it died

If their are other large draws on the system BOOM BOOM STEREO, 50+ Amp fans and A/C Then it might make a bit more sense. Way back when, one would toggle switch the field connection off at the drag strip to take the drag off the motor
thanks for trying to make a hard headed pollock understand the above

I added a 100 amp Power Master alternator to my last pump gas car, I disconnected and bypass the amp meter and installed a Volt meter. That alternator put out 14.5 volts constantly, not sure how many amps it put out though when idling after starting or 20 minutes later going down the road
I can remember more than one early (pre 1968) Mopar showing negative amps (discharging) on the stock amp meter when idling (less than 800 RPM in gear) at night with the lights on due to having a stock Mopar small output alternator

Ballast resistor is bypassed in start so you will have more voltage to the ECU in start than in run.

In a normally working system you have about 9v to the ECU in run, when the ballast resistor is bypassed you get full battery voltage, even if it battery voltage drops to 11v in start that is more than the ECU gets in run.

Every schematic I've seen has the ecu pin 1 getting full voltage in the run position with either a single or dual ballast ?