I would bet it is corona. For some reason, this particular system is running at a high enough voltage to cause corona, while your other vehicle isn't. If it bothers you, try swapping parts and see if you can find what is causing it. Maybe this particular coil is putting out a higher voltage, but it is usually limited by the spark gap. The voltage builds up to the point it will jump the gap and then it gets no higher.
Spark arc
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- #42
Charlie, OK, I'll swap coil and wires. Probably I won't pull and swap distributors because I'd hate to miss-seat one.
. Unless you think it's really wise to try.The plugs themselves I can't swap out because the F155 plugs have too long a reach, and I'd hate to dent my pistons
. (The plug gap, incidentally, is the same).I'm really hoping corona. I'd like to film it and post. Maybe I can figure out a way.
I googled "corona discharge" and came up with this. Sounds like it fits your situation.
Corona & Testing - Who, What, When, Where & Why
Don't pull the distributor; it doesn't have anything to do with this. Just the coil and wires.
Corona & Testing - Who, What, When, Where & Why
Don't pull the distributor; it doesn't have anything to do with this. Just the coil and wires.
Coolerman
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You may have corona discharge occuring but this statement "It reminded me of the sound a playing card makes when pinned to a bicycle yoke and it slaps against the wheel spokes." leads me to believe you have actual arcing occuring.
As Pin_Head pointed out, as long as the plug fires you have ignition. So if there is enough power in the lead you could still be firing the plug and arcing.
Try really hard to video this.
As Pin_Head pointed out, as long as the plug fires you have ignition. So if there is enough power in the lead you could still be firing the plug and arcing.
Try really hard to video this.
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- #45
Yep. Charlie, should I try a smaller gap on my plugs? How small?
Thanks!
Cripes. I reckon we are getting way tooooo scientific here.
Forget tampering with your plugs - From what you've done they're CERTAINLY NOT your problem.
It snaps like a spark. Therefore it is a spark!
You've spent a lot of dough already replacing stuff. (I suggested replacing the plugs only because they're cheap and that eliminates faulty plugs as being the culprit at minimal cost.)
How could it have been the leads if the spark wasn't coming off the leads? (Yeah - I know - I got it wrong with this in my first post too.)
And I believe a condenser fault would usually lessen the spark (and wouldn't tend to increase it - certainly not to that level anyway).
The spark voltage must surely be too high for some reason. (Ironic because most people have trouble with weak sparks.)
The coil (or more likely - the way the ballast resistor is working/not-working) is STILL more likely to be the issue now (in my view).
But you gotta get good footage of this arcing/sparking BEFORE you get on top of it ----- Please
Forget tampering with your plugs - From what you've done they're CERTAINLY NOT your problem.
It snaps like a spark. Therefore it is a spark!
You've spent a lot of dough already replacing stuff. (I suggested replacing the plugs only because they're cheap and that eliminates faulty plugs as being the culprit at minimal cost.)
How could it have been the leads if the spark wasn't coming off the leads? (Yeah - I know - I got it wrong with this in my first post too.)
And I believe a condenser fault would usually lessen the spark (and wouldn't tend to increase it - certainly not to that level anyway).
The spark voltage must surely be too high for some reason. (Ironic because most people have trouble with weak sparks.)
The coil (or more likely - the way the ballast resistor is working/not-working) is STILL more likely to be the issue now (in my view).
But you gotta get good footage of this arcing/sparking BEFORE you get on top of it ----- Please
Hey! What's wrong with science? It explains the way the world works, including your cruiser.
Corona also makes a crackling sound. If it was a spark, it would be visible in day light and the cylinder would misfire, since the chances of getting two sparks in parallel are vanishingly small.
I wouldn't make the spark gap smaller than the recommended gap of .035. Diferent plug wires (shielded, resistor) would probably take care of it. I would guess that the HV is probably traveling over the surface of the wire insulation.
Engineers (including automotive engineers) have known for over 100 years that too high of a voltage is a bad thing in many applications, like automotive ignitions. That doesn't stop huksters and snake oil salesman from pimping this as a way to make money by telling people that this will give them more engine power. It doesn't; it just makes things less reliable.
Corona also makes a crackling sound. If it was a spark, it would be visible in day light and the cylinder would misfire, since the chances of getting two sparks in parallel are vanishingly small.
I wouldn't make the spark gap smaller than the recommended gap of .035. Diferent plug wires (shielded, resistor) would probably take care of it. I would guess that the HV is probably traveling over the surface of the wire insulation.
Engineers (including automotive engineers) have known for over 100 years that too high of a voltage is a bad thing in many applications, like automotive ignitions. That doesn't stop huksters and snake oil salesman from pimping this as a way to make money by telling people that this will give them more engine power. It doesn't; it just makes things less reliable.
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- #48
But you gotta get good footage of this arcing/sparking BEFORE you get on top of it ----- Please
I know I'm running up against a language barrier, here (don't worry, my patients have this trouble all the time!
). I'd love to get good footage, but I don't know what that means in terms I can report!
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- #49
It is definitely a corona vs. a spark, by the visible in daylight definition (which implies the voltage at start and end being the same stuff in your reference). I'm definitely there.
Still, the consequences of the cause (overvoltage), tracking, insulation breakdown, etc, are probably the same in corona as in arcing, right?
If the voltage is traveling over the surface of the wires, should I not be able to see that, too, in a dark environ?
The main thing, I think, is to get rid of the cause, if I can determine what that is!
I won't mess with the gap.
I know I'm running up against a language barrier, here (don't worry, my patients have this trouble all the time!
Sorry IDave. By "footage" I just meant "film". ---- But then that word isn't really appropriate either with today's digital cameras.
So how about "photos" or "pictures" but as a "video clip posted on U-tube" (moving pictures with sound) because the CARONAS (see I DO believe you Charlie!) wouldn't be likely to show up well in simple "snapshots"?
Arcing and corona both are voltage dependent phenomena, but you can get a spark at a much lower potential than that required to ionize air molecules. Corona is especially bad because it can oxidize nitrogen to nitric acid, which is corrosive. I wasn't aware of this until I read the link.
I'm not as familiar with electrical coronas as I am with liquid Coronas, although I do admit to playing with Tesla coils in my youth. An igniton coil is basically a small Tesla coil.
You can see a corona anywhere there are ionized air molecules. My limited experience is that these ions tend to accumulate at the ends of the charged structures, like when you hold a broom stick up to a Tesla coil. That might be the end of the plug wire. I'm not sure.
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- #52
Duh. Yeah. Just have to wait until it gets dark, now.
Coolerman
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I thought a spark could only occur if the air WAS ionized?
The way I see it, you have these male electrons and female electrons having a party on your plug wires. The Corona is flowing... Things get going really good and soon get out of hand. Temps go up, the air gets ionized and BAM!!!
Houston we have an arc...
But that's just the way I see it...
The way I see it, you have these male electrons and female electrons having a party on your plug wires. The Corona is flowing... Things get going really good and soon get out of hand. Temps go up, the air gets ionized and BAM!!!
Houston we have an arc...
But that's just the way I see it...
corona effect
It is also know to be a problem at high altitudes what the heck are you doing with your cruiser?
You would think new clean wires would rule this out but????
I dont think it would hurt to lesson the gap and see what happens
Are all the wires doing it or just some????
Could you live with just telling people you have a photon generator under the hood?
Aurora Ignition Wires
Corona Effect and Spark Plug Wires
Corona effect, also known as Corona discharge, is a relatively rare phenomenon that can cause a glow on spark plug wires.
This event (visible in the dark) appears as a bluish-white glow around the spark plug wires, and may branch between wires or to an engine ground surface. Corona discharge does not necessarily indicate a problem with the spark plug wires but is more likely a maintenance or installation issue. This discharge is virtually silent as compared to the 'snapping' noise heard when a wire is actually leaking high voltage.
The cause of Corona discharge is the ionization (making conductive) of the surrounding air. Ionization releases electrons from the oxygen molecules and the resultant energy release creates photons (light) to be produced. This ionization is caused by the presence of large voltage differentials pulsing in the wire.
Certain contaminants on the jacket of a spark plug wire can enhance the liklihood of this phenomenon to appear, such as accumulation of oil or grease, dirt or paint overspray. Spark plug wire routing will also have an effect. If spark plug wires are allowed to touch an engine ground surface or if they are bundled together tightly, the chance of Corona discharge is greater. Alternate fuel vehicles, such as propane or natural gas powered, can see increased liklihood of Corona discharge as well. Residual vapors from these fuels cause easier ionization of the surrounding air.
To minimize the chance of Corona discharge, spark plug wires should be kept relatively clean and free of noticeable amounts of contaminants. Spark plug wires should also never rub against metal engine parts such as valve covers. Proper loom clips should be used to separate plug wires. Avoid bundling wires together with cable ties.
It is also know to be a problem at high altitudes what the heck are you doing with your cruiser?
You would think new clean wires would rule this out but????
I dont think it would hurt to lesson the gap and see what happens
Are all the wires doing it or just some????
Could you live with just telling people you have a photon generator under the hood?
Aurora Ignition Wires
Corona Effect and Spark Plug Wires
Corona effect, also known as Corona discharge, is a relatively rare phenomenon that can cause a glow on spark plug wires.
This event (visible in the dark) appears as a bluish-white glow around the spark plug wires, and may branch between wires or to an engine ground surface. Corona discharge does not necessarily indicate a problem with the spark plug wires but is more likely a maintenance or installation issue. This discharge is virtually silent as compared to the 'snapping' noise heard when a wire is actually leaking high voltage.
The cause of Corona discharge is the ionization (making conductive) of the surrounding air. Ionization releases electrons from the oxygen molecules and the resultant energy release creates photons (light) to be produced. This ionization is caused by the presence of large voltage differentials pulsing in the wire.
Certain contaminants on the jacket of a spark plug wire can enhance the liklihood of this phenomenon to appear, such as accumulation of oil or grease, dirt or paint overspray. Spark plug wire routing will also have an effect. If spark plug wires are allowed to touch an engine ground surface or if they are bundled together tightly, the chance of Corona discharge is greater. Alternate fuel vehicles, such as propane or natural gas powered, can see increased liklihood of Corona discharge as well. Residual vapors from these fuels cause easier ionization of the surrounding air.
To minimize the chance of Corona discharge, spark plug wires should be kept relatively clean and free of noticeable amounts of contaminants. Spark plug wires should also never rub against metal engine parts such as valve covers. Proper loom clips should be used to separate plug wires. Avoid bundling wires together with cable ties.
Text courtesy of Aurora Electronics Ltd.
Well you've definitely had too many Coronas Coolerman.
Yes, both coronas and sparks involve ionization of gas molecules. The difference is the way the energy is dissipated.
The difference is explained here:
Explosion and ESD
It is maybe more detail than you wan't to read.
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- #57
UGH
Well,
I tried but my canon g9 just doesn't seem to register this stuff on any setting, probably because I suck as much at photography as at electrical chores.
I've now replaced plugs, wires, coil, cap and rotor, and rubbed silicone based dielectric grease on the plug insulators and inner boots, all to no avail.
Yes, all plugs are involved.
Wire resistances were 6600, 5300, and 3100 ohms (long, medium and short wires). *edit toyota specs: should be 21 Ohms/mm*
Battery voltage was 14.27 volts at idle (500 rpm) and 14.83 volts at 2000 rpm, which for all intents and purposes was the same as my FJ40 with the same multimeter.
I'm not sure where to go next, except maybe another type of wire.
Well,
I tried but my canon g9 just doesn't seem to register this stuff on any setting, probably because I suck as much at photography as at electrical chores.
I've now replaced plugs, wires, coil, cap and rotor, and rubbed silicone based dielectric grease on the plug insulators and inner boots, all to no avail.
Yes, all plugs are involved.
Wire resistances were 6600, 5300, and 3100 ohms (long, medium and short wires). *edit toyota specs: should be 21 Ohms/mm*
Battery voltage was 14.27 volts at idle (500 rpm) and 14.83 volts at 2000 rpm, which for all intents and purposes was the same as my FJ40 with the same multimeter.
I'm not sure where to go next, except maybe another type of wire.
Last edited:
an interesting read on wires
Truth About Ignition Wire Conductors
some interesting reading on wires here especially shielded ones that are not all they are cracked up to be
Truth About Ignition Wire Conductors
some interesting reading on wires here especially shielded ones that are not all they are cracked up to be
Well. At least I'm in no danger of getting irradiated by your FJ40 over here IDave
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- #60
