Hoosier, thanks for that simple and obvious suggestion! I was thinking about buying one like it; never occurred to me to try a simple swap!

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

peeot

I think your coil is overheating because of TOO LITTLE RESISTANCE from your ballast not too much. Pete

My guess would be a faulty resistor on the firewall. Mine fell apart and ruined my coil.

I have not yet tried the Chrysler's Accel coil in the Fairlane because, to be honest, I'm afraid to mess with a good thing. I'm still planning to try it as a last resort. Wanted to put in another update before I proceed though, just in case...

Spent more time fooling around with it today, pretty much re-checking everything. It so happened that everything under the hood was exactly 75*F according to my temp probe, which is the exact spec the manual cites for all resistances, so I checked them. Ballast: 1.3 ohms. Coil primary: 1.3 ohms. Coil secondary: 8350 ohms. Coil current draw (engine stopped): 4.15A

Just for grins, I checked the Chrysler at the same time. I was surprised to find its ballast resistor read just 0.8 ohms.

Anyway. Started the car, drove it around to warm it up, everything's peachy. Got to the usual point where it would start up but not run. Swapped in a different condenser, no change, and inspected the points, which looked OK. No change. Only thing that makes any difference is bypassing the resistor, which makes it run great. Today the coil was not much over 100* when the problems started happening. When I bypassed the resistor, its temperature climbed substantially. Charging voltage was 14.5V; volts to coil post-resistor were around 12.

I noticed that I could thin the idle mixture out a half turn at idle in gear without any noticeable change in engine running, as long as the resistor was bypassed.

I am very suspicious that this coil is bad. It seems plausible that when the coil gets enough heat in it a short develops in the primary windings resulting in a weakened spark that can be "corrected" by boosting the voltage supply. It also seems plausible, as some of you have suggested, that the ballast resistor isn't doing its job and reducing the current sufficiently. Both components show basically the same resistances when the system is malfunctioning as when it is working properly, ALTHOUGH I think it is worth noting that the coil primary resistance DROPS a couple tenths when it gets warm while the secondary resistance climbs up about 1k ohms.

If the coil is bad, either a component external to it caused it to fail (such as the ballast resistor) or else the design of the particular coil I bought is not suited to its environment on the Fairlane's engine. Since I don't understand why the coil was getting so hot in the first place, and I cannot find any conclusive, measurable faults in specific parts, I'm left in the unenviable position of having to assume that at least one of the "new" parts is bad out of the box without any guarantee that the next I buy will be any better.

Should the resistor be knocking that 14.5V down below 12?

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

OK. The car that is in your garage thats works is NOT the FORD it IS the CHRYSLER. Do the same test on it and compare the results.

The VOLTAGE to the coil ( Ford or Chrysler ) should be the same. Go from there.

If the car quits and you have to bypass the resistor to get it to run, the resistor is opening when it gets warm. Bypassing the resistor will heat the coil. Check the resistance of the resistor when the car dies, you will probably find it open.

John - "The Hoosier Hurricane"

OK, it is beginning to look like I've been barking up the wrong tree.

I ran all of the same tests on the Chrysler and found it to have 10V to coil while seeing 14.5V at the battery. The coil voltage dropped below 8 at idle but there was no trouble.

I found an old mustard top coil I had, and tried that coil as well as the Chrysler's coil, a spare resistor, and the Chrysler's resistor all in the Ford, all with the exact same results. I also tried the Ford coil (that I believed to be faulty) on the Chrysler since Autozone listed the same coil for both cars. It chugged away without a hiccup regardless of the voltage or temperature it was seeing. Since the Chrysler's dwell spec was higher, and it was set at 30*, and I usually set my Fords to 28.5 but had this one set at 26, I tried increasing the dwell, which had no effect. In the end I left it at 28.5*.

Next I tried plugging the line for the wiper motor at the wiper motor; no effect. Then I plugged the choke thermostat hole. This was the only thing I tried other than bypassing the resistor that would let the car idle apparently indefinitely. There were still some hiccups in the idle but it didn't feel like it would stop, whereas normally it would stop within 5 seconds.

I sprayed around the carb base and manifold with water but found no vacuum leaks. My specs say that the carb mixture should be happiest about 1 turn from seated but it will not run below 1.5 turns. There is a calibrated orifice in the carb underside which meters vacuum to the choke thermostat so that is sort of a designed-in vacuum leak. The only thing that makes sense to me at this point is something that I thought I'd already addressed, which is air leaking past the secondary throttle plates, which have no idle ports, causing a leaning effect and poor low speed running. This does not account for the high-speed misfiring I had at the start of this trouble, but I don't know what else could be wrong. I can't find any faults in the ignition components and have even observed the engine stumbling and quitting, pretty abruptly, while my timing light showed continued flashes at the coil wire.

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

peeeot,

My experience with car engine that stop running is that a fuel problem is anything but sudden and gives a lot of warning while an ignition problem is very quick. Think light switch kind of quick. On/OFF. You appear to have a quick problem so I think it is electric.

The major players in this game are. bat, IGNITION SWITCH, resistor, coil, points, condenser, GROUND WIRE inside the distriburor, wires, plugs.

When you used the jumper wire from the bat positive post to the distributor you by passed your ballast resistor and your IGNITION SWITCH. Recheck the ground on the point plate ( little braided wire)

I have the feeling that your overthinking the problem. Remember keep it simple. Pete

Pete,

Thanks for sticking with me on this! You're probably right about overthinking, and I hope some silly little obvious thing ends up being the problem! I'm inclined to agree with you about sudden problems being electrical. I have focused on the electrical for that reason.

As for your list of major players, the battery is new. When I bypassed the resistor, I did so by disconnecting the wires at the resistor and putting them together, which keeps the ignition switch in circuit. The voltage drop across the switch was not substantial, either, but the part is cheap so if you think it's worth just replacing it I don't mind giving it a go. I have tried 3 different resistors, 2 new one old and known to be reliable, all with the same result. I have now tried 3 different coils, 1 new, 2 tested to be reliable with the same result. The points have less than 1000 miles on them and do not appear burnt or unusually scored. I have tried 2 different condensers (both new). The plugs are new and gapped on the smaller end of the range, .033".

The little ground wire inside the distributor looks just fine and the voltage drop across it seems fine BUT I haven't given it any special attention yet so I will. The secondary wires were installed before I bought the car but had never been used as the motor was stuck, so I consider them to be new.

EDIT: I pulled the distributor just now and made sure the ground wire was intact and making good clean contact at both ends. Upon reassembly, I had to skip the resistor again to get the engine to run slowly enough to set the timing up right. So still no improvement.

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

peeeot,

My bad. I left out a very important electrical player. The GROUNDS. Add a second ground from the engine to the chassis and clean the battery ground and both cable connections.

As frustrating as this is, weve all been there. Pete