59AB engine dies while driving at highway speeds

[Seth Swoboda]

While driving our 39 pickup today the engine dies without warning, just as if you threw the ignition switch to the "off" position. It did this 4 times while on an 8 mile drive. The engine is getting fuel so no problem there. When it died it did not sputter or "buck" it just dies. When I pulled off of the road and it sat for a few minutes it would restart and I could proceed another mile or so and it would die again. I did notice that the coil is extremely hot. So hot that you could not hold your hand on it but for a second. The engine starts and runs well but after a short time it will die suddenly.

Here is the set up.
59AB engine, 12 volts, two bolt crab distributor with electronic ignition & 12 volt coil. I also have a 12 volt generator.

We have voltage at the switch & coil. We also checked the coil with a volt meter and it seems to be good with around 1.8 ohms and the voltage checked out.

We then hot wired the ignition switch and then added a resistor to the input side of the coil thinking the coil was getting so hot it was breaking down or not producing spark. We hot wired the ignition switch to see if perhaps we had a faulty ignition switch. We tried this both ways with and without the resistor. While in the driveway it ran and the engine did not die. The coil seems to be getting too hot.

I have not had it back on the road since adding the resistor and I am a little spooked by this problem. This truck has just been completed and we are now working the bugs out of it so no real road milage on it yet.

Any ideas as to what is causing the engine to die?
Seth

Not looking for a debate on electronic,12 volt conversion. The Model A in my avatar has been running on electronic ignition, trouble free for over 10 years.

[1931 flamingo]

Some of the electronic ign need a good ground??
Paul in CT

[ford38v8]

Seth, I've heard that electronic ignition is very heat sensitive. If you get no spark through the distributor, you might pull the high tension from the coil and try it direct to a head bolt. This will show the problem as distributor or before distributor. As the coil gets hotter than hell, you should determine if it has an internal resistor and go from there.

[oldford2]

Oh, the joys and $ of converting to 12 volts and electronic ignition!
Keep things original and simple
John

[Gary in La.]

I would install another coil first. A correct good coil should not get that hot that fast and your symptons are typical of a coil breaking down.

[JM 35 Sedan]

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Seth, exactly how/where is the coil mounted? Is it possibly mounted in a hot spot? Insulations used in modern coils can break down and cause failure internal to the coil, just like a failure in an older coil, but probably less frequently. Do you possibly have another known good coil that you could interchange on the '39 pu just to see if the problem tracks with the coil? A typical or common failure mode with electrical or electronic components can be intermittent open or short circuit failure, in the presence of heat, that will sometimes temporary function correctly under cooler conditions. You should be able to isolate the faulty/bad component by changing one thing at a time until the problem disappears. Keep in mind that most all modern vehicles run extremely well on electronic ignition. If that technology had been readily available during Henry's time his engineers would have probably used it on your '39. Disregard the 'nay sayers' who make their extremly helpful comments.... always trying their best to be so encouraging in these situations. Keep trouble shooting the problem and I'm sure you will get it solved.

[BillM]

Bubba talks about coil ohms and ballast resistors in this post on the HAMB:
http://www.jalopyjournal.com/forum/s...81#post6680881
This is part of what he said:

We have three coils made for us here in Indiana ( USA) and we use a .5 ohms for electronics ( with current control) , and a 2.0 coil for use with a ballast as well as a 4.0 for use with contacts and no ballast .

Note he mentions current control for electronic ignition and .5 ohm coils; not all electronic ignitions have current control.
If your coil has gotten hot it may have damaged it.

[Bassman/NZ]

Amazing. Poor guy comes on here with a genuine question and gets a sermon.... sheesh.....

[ford38v8]

Yeah, Bassman, you're a big help too, aren't you?

[Mart]

I'd try another coil first.

I had a Buick once that I left the ignition on by mistake. It damaged the coil - oil leaked from the coil and it would get too hot and break down. Once cooled it would run ok again fro a while then break down again.

Could it be that the coil needs a ballast resistor and is getting too hot?

Can you try a known good coil and matching ballast from another car that is known to run well?

Mart.

[JM 35 Sedan]

Originally Posted by Bassman/NZ

Amazing. Poor guy comes on here with a genuine question and gets a sermon.... sheesh.....

YES, and it is even more amazing that some of the 'preachers' have had their own cars out of commission for over two years because they can't figure out how to get them running again!! And then they sometimes even post here how much and how long they drive their car while in fact their car sits broken in their garage....absolutely amazing

[Brad]

Seth
Try another coil 12v lots of good aftermarkets some have internal resistors or use a ballast from a Chryler

[Brad]

Coil voltage should be around 4.0 volts

[Seth Swoboda]

Originally Posted by JM 35 Sedan

Seth, exactly how/where is the coil mounted? Is it possibly mounted in a hot spot? Insulations used in modern coils can break down and cause failure internal to the coil, just like a failure in an older coil, but probably less frequently. Do you possibly have another known good coil that you could interchange on the '39 pu just to see if the problem tracks with the coil? A typical or common failure mode with electrical or electronic components can be intermittent open or short circuit failure in the presence of heat that will sometimes temporary function correctly under cooler conditions. You should be able to isolate the faulty/bad component by changing one thing at a time until the problem disappears. Keep in mind that most all modern vehicles run extremely well on electronic ignition. If that technology had been readily available during Henry's time his engineers would have probably used it on your '39. Disregard the 'nay sayers' who make their extremly helpful comments.... always trying their best to be so encouraging in these situations. Keep trouble shooting the problem and I'm sure you will get it solved.

JM,

The coil is mounted on the front of the engine (drivers side) on a bracket just above the head. I believe you and some of the others are on to something with this coil being bad, getting too hot and breaking down. I am going to call Bubba and talk it over with him Monday morning. Perhaps he can send me a different coil. I will keep trying to isolate the problem. I can't imagine that whatever it is causing the electrical problem is that difficult. Anyway, if you don't try new things, trouble shoot and solve problems then you will have learned nothing in your life. I will keep all of you guys posted on where the problem lies as I continue working on this.

You are also spot on when you said if Henry's engineers had the electronic ignition technology they would have used it. You bet they would have. I can tell you with 12volts and the electronic ignition, when I hit that starter button that flathead V8 starts like flipping a light switch. Virtually no cranking.

Thanks,
Seth

[Seth Swoboda]

When I was a kid (16 years old) I had my grandfathers 46 Ford coupe out and was driving it around. I brought it back to his house and decided I would give the car a good washing so that grandpa and I would be ready to attend a car show on that Sunday. When I pulled that car up in his driveway to wash it, I for some reason left the ignition switch on. I proceeded to wash the car and later when I tried to start the car it would not run. I consulted my grandfather and he came over to look at the car. He pointed out that I had left the ignition switch on for a long period of time and when we felt the coil it was HOT. Saturday evening and a bad coil meant no show in the morning. Well fortunately, a friend had a good coil in his garage that we installed on the 46 and we were all set to cruise.

I guess the point of this story is it reminds me of my current problem with the coil getting extremely HOT and the ignition suddenly cutting out. Just thinking back and trying to relate past experiences to todays problem.

[peteyshoes]

this screams of a faulty coil. if it's a resistor type coil, you can't have an external resistor before coil. 2 resistors, no-no. i have what appears to be the same system in my 42. had issues with resistor type coils. went with non resistor type and used a chrysler ceramic in line resistor after ign. switch. problem gone. keep us posted.

[DICK SPADARO]

I had a similar problem with an occasional use vehicle. Run fine and then skip or would not restart until it cooled down, wasnt fuel so it had to be ignition. Checked everything simple like points, condenser and coil. Problem still there. Took everything apart to individually test and everything ok. Put it back together and doing so found the coil had been wired backwards causing it to overheat and crap out. Swapped primary coil input wire connections and have had no problem since.

Easy check to see if the coil is wired correctly can be done by checking the primary wire leading from the coil to the distributor. If your vehicle is a + ground then the + termial of the coil should go to the distributor. Viseversa for negative ground vehicle. If you have a + ground vehicle and the distributor primary wire is hooked to the - coil terminal, its backwards. Thats my story on how I cured my problem.

[deuce lover]

Seth, I had the same exact problem.The coil I had had the internal resistor.Coil got so hot that I couldn't even touch it.Bubba suggested it was the coil.I bought one off EBAY, a Mallory coil for electronic ign and no more problems.I run a Mallory Unilite and have in the last 4 cars I built w/no problems.Oh yes my coil is mounted on the inner fender panel(36 coupe) and using the Malllory external resistor.PS I did run the car for 2 yrs with that previous coil and all of a sudden it went bad.Went to the meet in St George(10/2010) with it.Sheldon

[Henry/Kokomo]

Seth - I think your idea of contacting Bubba to discuss your situation will get you the quickest results. Personally, I agree with those who suggest it's a coil-related problem. Hang in there. You'll get it figured out.

[TomO]

The electronic ignition just replaces the points with a magnetic pickup and amplifier. Heat and electrical spikes can cause them to fail suddenly.

Points do not fail suddenly. You usually get a miss or poor fuel mileage warnings before they fail. Quality points are becoming hard to find, but you can usually get 20,000 miles from a set on the dual point distributors.