Took the fairlane out for its first lengthy drive in warmer weather. It was definitely running warmer than before but not outside of the "ok" bar on the gauge. Got a ways out when I started getting random misfiring at idle. From that point things got worse pretty rapidly and I was getting lots of random misses at all engine speeds. I pulled over at one point to let everything cool off with the hood open, the coil was too hot to touch for long. I waited about 15 min and there was slight improvement. I limped it home and parked it.

I thought maybe the ignition was seeing too much voltage due to the 15+ volts the (new) regulator was set at. Prior to this drive I'd reset the voltage at 80*F to just under 15, at the middle of the spec'd range per the manual. I rechecked output today and it was well over 15 again. I reset it to a little over 13, which is much less than spec'd. With all the lights and the blower on, engine at about 1000 rpm, the number was about 12.8. Even with the engine at idle speed, the coil was seeing about 10V.

After a while of running like this I started getting random misfires until the engine quit. I tried bypassing the resistor but it wasn't totally clear whether that helped. I think it might've. Still, I don't know why the coil would need more than 10V. I checked the voltage drop through the points using my ancient Engine Analyzer, and the drop was less than 0.2V. The engine would start up pretty easily after quitting but would run poorly and briefly. Dwell is at 26*, initial timing at 10*, resistor and coil resistances check out correctly. The coil was quite hot again so I swapped it for an old spare I had, the one that was on the car when I bought it. It fired right up but exhibited the exact same symptoms as the other coil.

I haven't tried replacing the condenser this time, but here's what bugs me: resistor, coil, points, condenser, plugs, dist cap and rotor, and wires have all been replaced in less than 1000 miles. The coil, an Autozone unit, has been replaced under warranty once in an effort to rule it out as a bad unit. My other car, a 1962 Chrysler, got all of these components replaced exactly once and has never had a hiccup in a couple thousand miles over several years; its coil is also mounted laying down on the engine. I don't want to believe that all of the ignition parts I can buy at the local store are unreliable junk.

Any ideas what I'm missing here?

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

You have looked at just about everything anyone could suggest.I have one suggestion.Find someone who has a professional scope and do a scope check on it.You are missing something obscure by the sounds of it.To keep replacing compinents and guessing isn't finding the problem.A scope test should be able to test various components when the car is running especially if you can get it to act up while its being tested.Just a suggestion.

  

Thanks oldcarmark. What kind of scope are you referring to? An oscilloscope?

Some of this reminds me of the past so I reviewed the following 2 topics from when I had my 292-powered '59 Galaxie:

http://forums.y-blocksforever.com/Topic28025.aspx

http://forums.y-blocksforever.com/Topic49335.aspx?PageIndex=2#bm49567

The first topic sounds remarkably similar so I will try swapping in a new condenser tomorrow. I distinctly remember the second topic, though, and how the new coil "fixed" it. That Accel Super Stock coil is what I run in the Chrysler. It is oil filled but at least in that car it doesn't seem to be a problem to lay it on its side.

IF replacing the condenser fixes it, though, I'm going to ask if ya'll can recommend a source for a condenser of reliable quality. I think it is strange that I have had 2 y-block Fords and had what appear to be the exact same ignition problems with both of them. I mention the Chrysler only because I'm buying my replacement parts from the same source without the same problems. I just want to replace a part and know that I can rule out that part as faulty rather than all of this second-guessing.

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

Yes.Someone who specilializes in tuneup/electrical would have a proper scope setup.

  

Today I found that everything stays OK as long as the engine stays above 1000rpm. Below that speed, the coil will get too hot and break down, at which point the problem will persist until it cools off.

This time, swapping in a cool coil for a hot one made an immediate difference. I monitored coil temperature and found that it is usually around 140*F on the hot engine. The coil quits around 150*.

I think if I moved the coil off of the engine to a cooler area it would be ok, but I want to keep it where it is.

Can anyone recommend a reliable replacement coil that can handle the heat of the engine and laying on its side?

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

peeeot

When I read your post I noticed you said

" The engine would start up pretty easily after quitting but would run poorly and briefly. Dwell is at 26*, initial timing at 10*, resistor and coil resistances check out correctly. The coil was quite hot again so I swapped it for an old spare I had, the one that was on the car when I bought it. It fired right up but exhibited the exact same symptoms as the other coil."

It is "the engine would restart pretty easily" part.

The ignition switch has two paths to provide 12 volts to the coil. First is in start and is STRAIGHT 12 volts.

Second is in run and provides THROUGH the ballast resistor and is 9 volts to the coil.

Try running a jumper with alligator clips ( that can be quickly disconnected ) from PLUS bat to coil and see what you get. Can`t hurt. Pete

Pete, I did as you suggested and found that the car would continue to run with full voltage to the coil, even with the coil upwards of 150*F.

I proceeded to check the primary ignition wiring for voltage drop. There was a total drop of 0.3V from battery to resistor, and about half of that was in the wire from the ignition switch to the resistor, which is strange because it was showing 0.1 ohms of resistance. Voltage drop to ground from the coil was 0.22V.

I don't understand why bypassing the resistor is "fixing" it. The manual indicates that a minimum of 8.5V at the coil is necessary. I have never seen a reading below 9.5V, even through the resistor.

I suppose what I'll do is run a new wire from the ign switch to the resistor and see whether that takes care of it.

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

By bypassing ballast and getting full 12 volt to coil is troubleshooting. Now isolate and correct the actual problem. Bad ballast. Bad ignition switch. Other. Do not run full 12 volt through a coil designed to run on 9 volts. Google it. Pete

I think there is more resistance in the primary circuit than there should be, and am going to work to fix that.

Could excessive resistance (and thus, voltage drop) in the primary circuit cause a coil to run hot?

I still think the coil is overheating. Now I'm trying to figure out why.

Incidentally, after driving around my Chrysler and getting it good and hot, I noticed that the coil was only a little warm and not at all hot. The coil on that engine is, however, mounted in front of the carburetor where the airflow from the fan hits it pretty directly.

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

How about trying the Chrysler coil on the Ford and seeing if it fixes your problem?

John - "The Hoosier Hurricane"