Engine dies, but turn the key off and back on it fires right back up

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Because the CAP and CAS advances used a fast and long primary advance. They did this to get timing where it needed to be for power and economy while running late timing at idle for more complete burn of HC and reduction of CO.
By shortening the slot on the inside like Rockable did here, then its pretty much a pre-CAP advance. Everything will work as it should without changing springs. Small adjustments on the start can be done by adjusting the spring perches.
I think how and why is pretty well illustrated with Rockable (360 Tune Up) and further discussed with Mullinax.
 
I have run them all and with all the holes in the inner fender to prove on resto. Most often it is just plain poor over All wiring that is the issue. If I still had all the boxes I have tried over the years It would be fun to experiment. Mallory seemed my worst. Bet my old gold box would be spot on today after replacing every wire in the car. It was the best I used in my years. Needless to say I am quite happy with Pertronix III and all Hidden away today. Over all The Full Wiring of the car is everything to Ultimate success!
 
I'm 4 years late to this but I saw a link to this topic from a guy at FBBO.
I'm dealing with a random NO spark issue where my '70 Charger (big block, MP electronic ignition kit) will do one of the following:
Run fine all the time.
Run, then just die and have no spark...I wait a little bit and it starts up normally.
Run, then just die and have no spark...swap parts until it starts (Who knows if anything helped, the damned thing may have started with no changes)
Cold start after sitting, no spark. Warm engine after running awhile won't have spark.
No spark cold or warm engine, spray ether down carburetor and it starts up like normal.

I'm cleaning the bulkhead terminals and packing the plugs with dielectric grease tomorrow.
 
I'm 4 years late to this but I saw a link to this topic from a guy at FBBO.
I'm dealing with a random NO spark issue where my '70 Charger (big block, MP electronic ignition kit) will do one of the following:
Run fine all the time.
Run, then just die and have no spark...I wait a little bit and it starts up normally.
Run, then just die and have no spark...swap parts until it starts (Who knows if anything helped, the damned thing may have started with no changes)
Cold start after sitting, no spark. Warm engine after running awhile won't have spark.
No spark cold or warm engine, spray ether down carburetor and it starts up like normal.

I'm cleaning the bulkhead terminals and packing the plugs with dielectric grease tomorrow.
Not sure why you got pointed to this thread. The OP replaced the ECU and solved his problem. It sounds like you have changed the ECU?
Lets think what we need to narrow the problem down.
I assume you are checking no spark with a spark tester. On #1 or on the coil wire?
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Glance at the ammeter next time this happens. If it shows a slight discharge then the ignition is still drawing some current. If not, then the ECU or distributor pickup or connections are suspect. Its a small draw so will not move the needle much. You'll have to be the judge on that.
if that is too subtle, then use a voltmeter to check for power at the coil and at the feed for the ECU. Or better use the ammeter and a portable voltmeter.

Coils will sometimes die intermittantly, but I;m leaning against that since you can restart immediately. Do check the connections though.

Since the ECU wiring is add on, check the new and old connections.

All of the above. How was the ECU wired in?

For example, if with the key in start there's no power to coil, then work back to the key switch. If there is power there, then check power feed to the ECU.
 
And if it does start, same thing. Check the power going to the coil and going to the ECU. Ammeter will be no help 'cause current will be flowing from the alternator. Or rather, it ought to be! Then when it does you'll have a reference. The problem is either in one of the devices (ECU, Coil, Distributor) or in the power feed to one or both (ECU and coil). If there is power then there is the possiblity of distributor not signalling or the ECU not getting the magnetic pulse. Do the easy checks first to narrow it down. Just typing it now 'cause I won't be at the computer later.
(I'm assuming here everything else works when there is no spark. Not sure? turn on dome light or step on brake, then check somehting that requires the key on - radio - heater - wiper.)



1711280714062.png
 
When all else fails remember;
voltage is pressure/amps is flo.
You can have full voltage into a device, yet the device won't work cuz there are just not enough electrons able to pass into thru or out of the device.
This fact has frustrated more than a few shade-tree mechanix.
What I mean is this;

You can take a multi-strand wire and separate the wires at one end, then connect just one of those strands to a power source. Inside the wire-bundle, the strands are all touching eachother, and so, on the other end, every strand will show the voltage of the source.
You might be able to measure the source-voltage with your VOM just fine, and you might be able to power-up an LED bulb Test-light with it. But just try powering anything up on your car with it.
When in doubt, always try pulling some amps thru a suspect-wire/circuit.
 
You can have full voltage into a device, yet the device won't work cuz there are just not enough electrons able to pass into thru or out of the device.
True.
Had it happen on a jeep I was working on for someone. One of the battery cables had just enough of a connection internally, but once the starter put the circuit under load, everything would got out and stay out until the cable cooled off. Jumper wires, jumper cables and a test light can find an issue like that better than a volt meter sometimes.
 
I battled a no spark issue for a while,and finally found the rotor was bad,burned through. It would stall more when humidity was high.
 
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