Hi all,

I have been puzzling with my motor on and off for a couple weeks. I am hoping to get some insights as to why my motor would not continue running once I release the "start" switch. I get a steady ignition noise (the sound of pistons firing and the engine gets warm), but once I release the "start" position the engine dies. I just measured the power coming from the top of the coil (as it would go to the distributor) and it reads 1.32 when set to the 20k DC setting. If I let it sit it starts to drop, quickly at first then slows, all the way down to 0.82 after ten minutes. I think it would keep dropping but stopped there.
Not sure if that description helps.

Any insights as to why it won't stay running? The engine is out of the car and mounted to a pallet if that helps at all.

Sincerely,

Paul

It would be helpful if you would sketch out a drawing detailing how you have the engine / test stand wired.

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Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

Trace the "RUN" wire back to the bulkhead connector and check the contacts in the connector. It will probably be a blue wire. Check the ballast resistor for continuity too.

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Official Cookie and Mater Tormentor.

Our 74 & 75's have a "start-run" relay near the ballast resistor. That relay has shut us down several times, mostly due to dirty contacts inside.

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"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

Dual ballast resistor? Sometimes the run side burns out.

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Hyper_pak

I will try and sketch out my wiring diagram tomorrow and will upload the picture.

Thanks

Paul

Hi all,

Below is my diagram. I hope it is clear enough to make sense of. Looking at everything as I drew this I wonder if I got the solenoid and ignition to resistor wires switched.

Sincerely,

Paul Barrow

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Joshua

that solenoid to ballast wire is just the full 12v "kick"/ "ballast bypass during start" I wouldn't think the ignition would bleed that much, from the starter solenoid's function.....

What's your wager?

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Joshua

Thanks guys,

I suppose one question to ask would be is there any way I could wire this incorrectly that would cause damage? If not, I will try your suggestion tonight Joshie.

Thanks again,

Paul

Since it seems to want to fire while cranking, I wouldn't think the start circuit is the problem.
You say that it dies when the key is released to the run position so I would look at that part of the circuit, especially the ballast itself.
What is the voltage at the coil with the key in the run position?
You might try bypassing the ballast temporarily as an experiment.

By the way, nice job on the schematic

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O==\=/==O

"A mechanic is Somebody."
- Jim Preston

If he bypasses the ballast resistor without making other changes to his wiring the starter will engage when the ignition switch is on. The interconnection between the starter solenoid and the ignition must be removed.

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Joshua

True - hence your point about properly wiring the bypass.
A temporary 'run' bypass is usually considered 'hot-wiring', such as a wire straight from B+ to the coil.

I'm sorry for not more clearly making the connection

_________________
O==\=/==O

"A mechanic is Somebody."
- Jim Preston

Yeah didn't think about that.
I'm thinking of the old 4 pin ballast and 5 pin ecu,not the 2 pin ballast and 4pin ecu. I was thinking if he went off of the same terminal from the starter relay that the small wire on the starter solenoid is wired from that it would be a safe way to go but maybe not