Plasma Ignition | Plasma Jet Ignition

[Aaron Murakami]

Forget about the diodes for a moment! Please re-read what I have posted! It misfires with NO DIODES ATTACHED! AGAIN, When only my wire is attached to the plug cable with NOTHING attached on the other end it causes the whole engine to misfire???

I'm sorry but you are wrong about the busbar wiring, it is a common connection for the 4 diodes on that common end that connects to the coil but STILL that is a moot point because as I have described several times before it misfires with no diodes or busbar connected to any of my wiring??

If you notice in the pic there is NOTHING connected to the other end of my red diode jumper wire and just having that wire plugged into my modified cable it completely screws up the spark for the plugs to fire properly???

Connecting all diodes together at the end that goes to the coil + and each diode going individually to their own plug is definitely correct. The only diode that will be used like that will be whatever plug fires, the the rest of the cap discharges through that diode over the gap.

If the distributor cap arcing is a problem, it's feasible but would be the first time I've heard of anyone encountering that problem.

The previous owner of the Datsun I have changed the distributor's points/rotor systems to an electronic ignition so I never had the opportunity to have that problem if that is what is even happening. That is one option possible is that if that is a problem, you could replace the distributor with an electronic ignition. Then you just use the magnetic pickup input for the MSD.

As far as your hookup goes, it's correct. Each diode to the wire spiced into the ignition cables should be just fine.

Although you tested the diodes in both directions and get a spark in one direction but not the other, I would still do the definitive test with the ignition coil HV output to see the polarity with the pencil test.

[Gary Hammond]

Hi Rokan,

It appears in the photo you posted, and from your description, that you have three separate wires spliced together underneath some electrical tape. If so, this would be a prime location for the high voltage to short to ground and cause misfiring. Is this a soldered joint, or what kind of connection did you make here?

It's also possible that the short length of zero resistance wire that attaches to the plug is emitting enough RFI to disrupt either the electronic triggering device in the distributor or the MSD module itself. If it's RFI causing the problem, you may need to replace the whole set of plug wires with low resistance (40 to 350 ohms/ft), magnetic cored, spiral wound wires and then fasten the diode wires directly to the plug terminals inside the plug boot. That's what I did on my high performance air cooled VW engine, and it runs great all the way up to it's 6000 RPM redline.

[rokan]

Of course you do. don't we all? English is the most precise and clear language, after all.

I'm looking at the first pic in post #939 with a bunch of red and grey ignition wires run to a component behind a cooling hose. I'd like to see that component more clearly before I apologize for offending.

busbar on diodes: trying to picture the energy flow in that configuration to help wrap my head around the misfire. why isn't each diode connected to the secondary of the coil individually? the way you have it (I think), the electrical energy flying around the engine fails to be targeted at the cylinder that needs to fire and goes everywhere. (the diodes clamp down AT/above a specific voltage but are otherwise open, and that voltage may be enough to cause a spark where there usually isnt one, right?)

I like the idea of running it in the dark...

Forget about the diodes for a moment! Please re-read what I have posted! It misfires with NO DIODES ATTACHED! AGAIN, When only my wire is attached to the plug cable with NOTHING attached on the other end it causes the whole engine to misfire???

I'm sorry but you are wrong about the busbar wiring, it is a common connection for the 4 diodes on that common end that connects to the coil but STILL that is a moot point because as I have described several times before it misfires with no diodes or busbar connected to any of my wiring??

If you notice in the pic there is NOTHING connected to the other end of my red diode jumper wire and just having that wire plugged into my modified cable it completely screws up the spark for the plugs to fire properly???

[heysoundude]

I speak perfect English! I guess you aren't understanding exactly what is going on and how the circuit is wired? 1 side of ALL of the diodes is connected to the positive of the coil, thus the bus-bar connecting ALL the diodes together and thus using 1 wire to connect to the coil. And then the other end on each diode is connected individually to each plug.
I will work on the coil/igniter circuti when I can dig up that exact info.
What coil are you looking at? There is NO coil near the plug ignition wire? Maybe you are confusing my modified plug wire which has a connector protected with plastic tubing that is used for my diode wire connection.
It is not waste spark ignition, it fires one cylinder at a time as the rotor spins inside the distributor cap.

If you look at the 2nd pic in #939 it shows exactly what my modified spark plug wires look like without having the engine in the background.

Of course you do. don't we all? English is the most precise and clear language, after all.

I'm looking at the first pic in post #939 with a bunch of red and grey ignition wires run to a component behind a cooling hose. I'd like to see that component more clearly before I apologize for offending.

busbar on diodes: trying to picture the energy flow in that configuration to help wrap my head around the misfire. why isn't each diode connected to the secondary of the coil individually? the way you have it (I think), the electrical energy flying around the engine fails to be targeted at the cylinder that needs to fire and goes everywhere. (the diodes clamp down AT/above a specific voltage but are otherwise open, and that voltage may be enough to cause a spark where there usually isnt one, right?)

I like the idea of running it in the dark...

[rokan]

what I'm confused about is what looks like a bus-bar across the diodes in your pic, @rokan. I'm not sure why you've connected the diodes like that. Could this be why you're getting misfires?

EDIT:

I see what you're doing now, I think.
I'm not sure you've applied this correctly.
Is it possible that you're unclear on some of the terminology, as in, something is being lost in translation from/to English?
Could you show us your distributor and coil/igniter and how the factory set it up, before your modifications? I ask because the wire you show in post #939 looks like a coil near plug ignition wire to me, and that's different than the traditional coil-cap-rotor setup Aaron designed for. Also, a 1996 model year whatever (toyota? honda?) probably has a waste spark ignition.

EDIT2:
Yup, that totally looks more like a waste spark coil than a distributor to me...but it's also likely that I could be mistaken. Any chance you can get the wires out of the way and try your best to not have it shadowed? (yes, I know you'll need more hands/arms to do that)

I speak perfect English! I guess you aren't understanding exactly what is going on and how the circuit is wired? 1 side of ALL of the diodes is connected to the positive of the coil, thus the bus-bar connecting ALL the diodes together and thus using 1 wire to connect to the coil. And then the other end on each diode is connected individually to each plug.
I will work on the coil/igniter circuti when I can dig up that exact info.
What coil are you looking at? There is NO coil near the plug ignition wire? Maybe you are confusing my modified plug wire which has a connector protected with plastic tubing that is used for my diode wire connection.
It is not waste spark ignition, it fires one cylinder at a time as the rotor spins inside the distributor cap.

If you look at the 2nd pic in #939 it shows exactly what my modified spark plug wires look like without having the engine in the background.

[Richard]

This distributor has an igniter module mounted on the fender well, could that be part of the problem?

Or maybe I need to completely remove the internal coil from the distributor? Even though it makes up a good portion of the distributor I could always tape off the exposed area I guess??

Have you looked at the engine running in the dark? Arcing shows up much better in the dark.

Richard Gieseer

[heysoundude]

what I'm confused about is what looks like a bus-bar across the diodes in your pic, @rokan. I'm not sure why you've connected the diodes like that. Could this be why you're getting misfires?

EDIT:

I see what you're doing now, I think.
I'm not sure you've applied this correctly.
Is it possible that you're unclear on some of the terminology, as in, something is being lost in translation from/to English?
Could you show us your distributor and coil/igniter and how the factory set it up, before your modifications? I ask because the wire you show in post #939 looks like a coil near plug ignition wire to me, and that's different than the traditional coil-cap-rotor setup Aaron designed for. Also, a 1996 model year whatever (toyota? honda?) probably has a waste spark ignition.

EDIT2:
Yup, that totally looks more like a waste spark coil than a distributor to me...but it's also likely that I could be mistaken. Any chance you can get the wires out of the way and try your best to not have it shadowed? (yes, I know you'll need more hands/arms to do that)

[rokan]

This distributor has an igniter module mounted on the fender well, could that be part of the problem?

Or maybe I need to completely remove the internal coil from the distributor? Even though it makes up a good portion of the distributor I could always tape off the exposed area I guess??

[rokan]

I wish I had a clear distributor cap to watch what is going on inside there!

The way I designed my plug wires there is only 0 resistance inside the plug boot that goes into the valve cover and about 3" on the outside and above that 3" it is the original resistance wire clear back to the cap. So the whole wire is not 0 resistance, only the bottom third going to the plug.
I like your explanation, I just don't know how to get around it yet if that is the case??

Please refer back to my post #939 and look at my plug wire. It only starts running bad when I connect the red jumper lead that would go to my diode and it runs bad when that lead is connected at the wire of the plug wire but connected to nothing on the diode end, just into the air???

[rokan]

I totally agree! So WHY would it run like s--t with no resistance and good with the resistance? The way I designed my plug wires is the top 2/3 is resistance coming out of the distributor cap and the bottom 1/3 going to the plug is no resistance wire so that I can deliver full voltage to my non-resistor plugs. BUT when anything is connected to that bottom 1/3 it will not run at all???

Ok, more testing!
There is no arcing inside the distributor cap that is visible anywhere inside the cap?? As I said before when my diode connector wire is attached to my plug wire and nothing is attached to the other end I can hear arcing inside the wire, hmmm? And when it is attached to only 1 wire the whole engine misses and runs horribly until it just dies? If it was only missing on the one plug wire I am attached to then the engine would run but only on 3 cylinders BUT this causes the whole engine to run so terribly that it coughs and sputters until it stops running completely!!??

Something, but what, is feeding back into the whole ignition system from just 1 wire?

What am I missing here?

Bewildered and perplexed,
Ron

[Richard]

I totally agree! So WHY would it run like s--t with no resistance and good with the resistance? The way I designed my plug wires is the top 2/3 is resistance coming out of the distributor cap and the bottom 1/3 going to the plug is no resistance wire so that I can deliver full voltage to my non-resistor plugs. BUT when anything is connected to that bottom 1/3 it will not run at all???

The voltage output of your ignition system is too high for the components like your distributor cap and rotor if my guess is correct. Any resistance in the high voltage circuit will bring the voltage of the other components down. Just to pick numbers without trying to be accurate, lets say your ignition coil puts out 30,000 volts. Say 20,000 volts is used to jump the spark plug gap, 1,000 volts is lost across the rotor to distributor cap and 9,000 is used up in the high resistance ignition wire and everything runs pretty good. Then replace the high resistance wire with a near 0 resistance wire and the loss in the wire goes from 9,000 volts to nearly 0 volts loss, but the ign coil is still putting out 30,000 volts and the plug is still using only 20,000volts. That extra 9,000 volts is looking for a place to go and the distributor designer did not design for that high a voltage and they did not give enough space between components like internal distributor cap contact points or the metal body of the distributor so the voltage is now high enough to arc to those parts inside the distributor and once it starts to arc it will rob from the plug. There's a thunderstorm inside the distributor, sparks are going everywhere and shorting out voltage that is needed at the plug. A little moisture, oil or dirt inside the cap can aggravate this problem. Have you tried washing the cap out with alcohol, then don't put your fingers on the cap and use a clean paper towel to handle it. You are asking it to perform at a higher voltage than what it was designed for. That's why I want to convert my engines to direct ignition, no high voltage in a distributor rotor and cap. Have you tried running it at night so you could better see any external arcing at the distributor or wiring?
This is all speculation on my part but at this distance that's about all I can do and it is all based on solid electronic theory. I hope someone else will chime in if they see any holes in my theory here. We are all here to both learn and share knowledge to help further the cause.
Whatever you find, please keep us all informed.

Richard Gieser

[rokan]

Any resistance in the circuit will drop voltage across that resistance thereby leaving less voltage to arc in the distributor cap. We want the highest voltage possible to reach the spark plug but not high enough to jump through the ignition wires to the valve covers, etc. or to arc in the dist cap. So ignition wires with resistance will eat up some of your voltage leaving less for the plug an dist cap.

I totally agree! So WHY would it run like s--t with no resistance and good with the resistance? The way I designed my plug wires is the top 2/3 is resistance coming out of the distributor cap and the bottom 1/3 going to the plug is no resistance wire so that I can deliver full voltage to my non-resistor plugs. BUT when anything is connected to that bottom 1/3 it will not run at all???

[Richard]

But why would it run perfectly ok with 5k resistance but when I remove the resistance it goes wacky??
I looked for traces in the cap and didn't see any but I will look again just to make sure.

Any resistance in the circuit will drop voltage across that resistance thereby leaving less voltage to arc in the distributor cap. We want the highest voltage possible to reach the spark plug but not high enough to jump through the ignition wires to the valve covers, etc. or to arc in the dist cap. So ignition wires with resistance will eat up some of your voltage leaving less for the plug an dist cap.

[rokan]

Sounds like arcing inside the distributor cap to me, the higher the voltage the worse it gets. Look inside the distributor cap for burned arcing traces. Maybe try a new distributor cap and wash it out with alcohol first.

Richard Gieser

But why would it run perfectly ok with 5k resistance but when I remove the resistance it goes wacky??
I looked for traces in the cap and didn't see any but I will look again just to make sure.

[Richard]

I just did another test.
I made one plug wire that was non-resistor and it didn't like that!
WHY???

Sounds like arcing inside the distributor cap to me, the higher the voltage the worse it gets. Look inside the distributor cap for burned arcing traces. Maybe try a new distributor cap and wash it out with alcohol first.

Richard Gieser