Plasma Ignition | Plasma Jet Ignition

[Aaron Murakami]

Here's the response I received from Ryan:
Does my Nology Profire PFC-M70 coil output HV positive or HV negative?

positive

Is my coil suitable for the MSD Street Fire MSD unit? Is it compatible with capacitive discharge?

M75 would be better, but M70 will work

What is the resistance for the primary?

.25 Ohm

What is the resistance of the hv secondary?

8 Ohm

That makes things simple being positive - always my preference.

That resistance is pretty low too - looks good.

If the hv output is truly positive, then this is how the diodes should be pointed. This of course doesn't address you possible rf problem, which I'm not so sure about or igniter issue if there is one.



Just to re-confirm, is this how you have your diodes or had your diodes?

[rokan]

I sent the info but didn't hear back.

[email protected] - Ryan Brewer

This is what I asked:

Does the Nology Profire coil output HV positive or HV negative?

Is this coil suitable for the MSD Street Fire MSD unit? Is it compatible with capacitive discharge?

What is the resistance for the primary? What is the resistance of the hv secondary?

Thanks!

If you can email him with the same questions, maybe that will prompt a response. Give the model # of the coil with the questions of course.

Here's the response I received from Ryan:
Does my Nology Profire PFC-M70 coil output HV positive or HV negative?

positive

Is my coil suitable for the MSD Street Fire MSD unit? Is it compatible with capacitive discharge?

M75 would be better, but M70 will work

What is the resistance for the primary?

.25 Ohm

What is the resistance of the hv secondary?

8 Ohm

[Aaron Murakami]

Hi Aaron,
Did you have a chance to speak with Nology yet?
Thx,
Ron

I sent the info but didn't hear back.

[email protected] - Ryan Brewer

This is what I asked:

Does the Nology Profire coil output HV positive or HV negative?

Is this coil suitable for the MSD Street Fire MSD unit? Is it compatible with capacitive discharge?

What is the resistance for the primary? What is the resistance of the hv secondary?

Thanks!

If you can email him with the same questions, maybe that will prompt a response. Give the model # of the coil with the questions of course.

[rokan]

Ron, what is the exact part # of your ignition coil? Nology got back to me and they can confirm a few things.

Hi Aaron,
Did you have a chance to speak with Nology yet?
Thx,
Ron

[rokan]

Ron, what is the exact part # of your ignition coil? Nology got back to me and they can confirm a few things.

I think it is the PFC-M70, it's been a LONG time since I bought it?? Pretty sure that is it.
Yep, double checked it and it is the M70.

[Aaron Murakami]

Ron, what is the exact part # of your ignition coil? Nology got back to me and they can confirm a few things.

[Gary Hammond]

Hi Ron,

Can the RF be that strong to completely disrupt the whole ignition circuit to completely mis-fire?

The longer the antenna is, the stronger the RFI signal is. If RFI is really the problem, you should be able to pick it up pretty loudly on a small portable radio held under the hood of the vehicle. And probably even on the vehicle's own radio. (And maybe even the neighbor's radio which the FCC won't like. )

If instead something is shorting out, you should be able to see it after dark.

any ideas that would be good for cap values? I am assuming polarized caps, right?

I would use whatever value the original cap in your distributor is. Or you could use caps like were used on old points and condenser ignition systems. They also used to have caps on the vibrating voltage regulators and even on the brushes of the old DC generators. As best I can remember, these fell somewhere between .47uf and 3mf at from 25 volts to 150 volts.

[rokan]

I still don't understand WHY when only one wire is attached to 1 T junction that goes to the top of 1 spark plug and the other end is attached to NOTHING WHY does it cause the engine to mis-fire so badly it won't run???

Can the RF be that strong to completely disrupt the whole ignition circuit to completely mis-fire?

[rokan]

I still don't understand WHY when only one wire is attached to 1 T junction that goes to the top of 1 spark plug and the other end is attached to NOTHING WHY does it cause the engine to mis-fire so badly it won't run???

[rokan]

Hi Ron,

I'm about to run out of ideas, but thought of a few things you might want to try to see if RFI is really the culprit here.

#1- Be sure all your connections are good and solid - no resistance. This includes all grounding connections.

#2 - Install capacitors to all 12 volt positive connections of the MSD module, the igniter, and the computer to help filter out RFI. These need to be as close to each component as possible.

#3 - Use shielded cable to hook up the diodes to both the coil and the T-junction and be sure to ground the shield.

#4 - If none of this helps try putting a Faraday cage around the computer fabricated out of steel screen or hardware cloth.

Great ideas!
#1 has been done
#2 I will have to try that, any ideas that would be good for cap values? I am assuming polarized caps, right?
#3 I used some tv cable and grounded the shield that surrounds the cable with no difference in performance (it still misses)
#4 I will have to give that a try also

Thank you for all of your great ideas!

[Gary Hammond]

Hi Ron,

I'm about to run out of ideas, but thought of a few things you might want to try to see if RFI is really the culprit here.

#1- Be sure all your connections are good and solid - no resistance. This includes all grounding connections.

#2 - Install capacitors to all 12 volt positive connections of the MSD module, the igniter, and the computer to help filter out RFI. These need to be as close to each component as possible.

#3 - Use shielded cable to hook up the diodes to both the coil and the T-junction and be sure to ground the shield.

#4 - If none of this helps try putting a Faraday cage around the computer fabricated out of steel screen or hardware cloth.

[rokan]

Hi Ron,

As you said, theoretically it should work!

I still have a few questions though.

#1 - Did you splice the negative coil wire from the igniter and MSD white wire together inside the distributor or outside of the distributor? (Where is the splice located?)

#2 - Which MSD wire did you splice to the other coil wire coming from the igniter and where is this splice physically located?

#3 - Do you still have a condenser fastened to the positive coil wire coming from the igniter that the other MSD wire is spliced to?

I'm wondering about Radio Frequency Interference to either the igniter, or the MSD module, or between the two (or maybe even the magnetic pickup and computer and wiring). Fastening a wire to the T-junction may cause it to become an antenna with nothing else attached.

#4 - Did you fasten the High Voltage Diode up to both the T-junction and coil positive at the same time to check for plasma? Or did you only try running the engine with the diode completely removed? (Wondering about RFI from an open antenna effect.)

#1 - At first I spliced to the negative coil wire inside the distributor and now I have it outside the distributor
#2 - No other MSD wire is connected to the other coil wire but I did try connecting the small red wire to the positive wire of the coil and it ran the same
#3 - No
#4 - I did both, there was some VERY strong spark/plasma but it would only run 5 - 10 seconds before completely shutting off

Somehow RFI must be the problem but it doesn't matter whether it is an open wire or closed with a diode??? How can it be soooo sensitive with only one wire and/or diode connected?

[Gary Hammond]

Hi Ron,

As you said, theoretically it should work!

I still have a few questions though.

#1 - Did you splice the negative coil wire from the igniter and MSD white wire together inside the distributor or outside of the distributor? (Where is the splice located?)

#2 - Which MSD wire did you splice to the other coil wire coming from the igniter and where is this splice physically located?

#3 - Do you still have a condenser fastened to the positive coil wire coming from the igniter that the other MSD wire is spliced to?

I'm wondering about Radio Frequency Interference to either the igniter, or the MSD module, or between the two (or maybe even the magnetic pickup and computer and wiring). Fastening a wire to the T-junction may cause it to become an antenna with nothing else attached.

#4 - Did you fasten the High Voltage Diode up to both the T-junction and coil positive at the same time to check for plasma? Or did you only try running the engine with the diode completely removed? (Wondering about RFI from an open antenna effect.)

[rokan]

Hi Ron,



I don't think the igniter can be completely removed, because it also is connected to the tachometer, the heated oxygen sensor, and data link connector.



I don't fully understand what you just explained. The two "coil wires" coming out of the distributor ----- are these the wires connected to the yellow and green wires inside the distributor? If so, this would be the white and black trigger signal wires that go to the computer (these should hook only to the computer)? Or do you mean the two wires from the igniter that originally hooked to the internal coil (black w/red tracer and black w/white tracer)? What wires from the MSD unit are hooked to these?



The white wire ------is this the white wire from the MSD box that is supposed to be used with breaker points? If so, this is what's triggering the MSD box and is getting it's signal from the igniter and should work. The igniter mimics a point and condenser set and is controlled by the computer.

I assume you have the orange wire and black wire from the MSD unit connected to the Nology coil primary terminals, correct?

The two coil wires do not connect to the yellow and green magnetic pickup wires and Yes the two coil wires that come from the igniter that go inside the distributor and attach to the original coil, the white MSD wire connects to the negative wire of the internal coil wires and that white wire is for points or electronic ignition amplifier from what the MSD instructions say
And yes, I do have the orange and black MSD wires connected to the Nology coil

Theoretically it should work BUT whenever I connect anything to the T junction of my spark plug wire so as to ad the plasma spark to it the engine completely misfires!? And that is only connecting 1 wire to #1 spark plug even when NOTHING is connected to the other end of that wire???

[Gary Hammond]

That little red wire goes to a condenser set down into the distributor housing

My best guess is the condenser was probably there to help filter out back spikes from the original coil and prevent them from messing with the magnetic pickup.