Plasma Ignition | Plasma Jet Ignition

[rokan]

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

[rokan]

Hi Aaron,



I didn't see that at first glance and was wondering about it after my last post. I suspect it provides 12 volts (+) to the magnetic pickup since it fastens to the coil (+) terminal along with the wire coming from the ignition switch. This complicates matters as the magnetic pickup will still need 12 volts (+) on this lead to trigger the computer. But the coil has to be separated and driven only by the MSD orange and black wires.

In order to retain and use the stock coil, a new (fifth) lead will have to enter somewhere other than thru the existing connector which has only four leads. (Can't use lead sharing when driving the coil with the MSD.)

If the external coil is used then the original coil must be disconnected or removed (and replaced with some type of filler block shaped like the coil) and the lead from the ignition switch then connected directly to the red wire you asked about going to the magnetic pickup. If the coil is only disconnected and left in place as a filler block, the secondary terminal will need to be removed and well insulated from it's original contact with the cap.

This is not an easy vehicle to modify, but I think it can be done.

I think we need to leave the igniter in the circuit for the computer to operate properly??
If we could make the stock coil work that will be fine but I already have it bypassed and am using the Nology coil now. I currently have the 2 coil wires coming out of the distributor that I have connected to my MSD unit, again with the white wire connected to the - wire of the stock coil to get my engine to run at this time.
I have already modified the cap to separate the internal coil from the center post plus both wires have been disconnected form the internal coil.

[Gary Hammond]

Hi Aaron,

What is the red wire from the + of the coil to the back of the magnetic pickup in the pics?

I didn't see that at first glance and was wondering about it after my last post. I suspect it provides 12 volts (+) to the magnetic pickup since it fastens to the coil (+) terminal along with the wire coming from the ignition switch. This complicates matters as the magnetic pickup will still need 12 volts (+) on this lead to trigger the computer. But the coil has to be separated and driven only by the MSD orange and black wires.

In order to retain and use the stock coil, a new (fifth) lead will have to enter somewhere other than thru the existing connector which has only four leads. (Can't use lead sharing when driving the coil with the MSD.)

If the external coil is used then the original coil must be disconnected or removed (and replaced with some type of filler block shaped like the coil) and the lead from the ignition switch then connected directly to the red wire you asked about going to the magnetic pickup. If the coil is only disconnected and left in place as a filler block, the secondary terminal will need to be removed and well insulated from it's original contact with the cap.

This is not an easy vehicle to modify, but I think it can be done.

[Aaron Murakami]

Hi Ron,



According to the schematic two wires (the solid black and the solid white wires in the schematic) connect the two magnetic pickup wires inside the distributor (yellow wire and green wire in photo) and go from the connector directly to the computer.

The other two wires that go thru the connector, go to the primary winding of the coil. The black w/ red tracer wire is a 12 volt (+) lead from the ignition switch to the positive side of the coil primary and also supplies 12 volts (+) to the igniter. The black wire w/ white tracer goes to the igniter and would be the momentary ground (-) connection for the coil every time the computer tells the igniter to fire (just like a set of points and condenser would). The igniter gets it's signal from the black wire w/ blue tracer and black wire w/ yellow tracer coming from the computer to the igniter.

It appears to me that you have two options with this setup. One is to rewire the stock coil to work with the MSD module, and the other option is to completely remove the stock coil and use the Nology ProFire coil you purchased. Either way the igniter will have to be bypassed and it's trigger signal from the computer also applied to the MSD module. 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 connecter.

Let me know which option you want to use and I'll help you figure out the connections to do it.

What is the red wire from the + of the coil to the back of the magnetic pickup in the pics?

[Gary Hammond]

Hi Ron,

Awesome! Thank you for the schematic!
Here are some pics of the inside of my distributor.
Aaron,
I tried wiring it like you said and it won't start that way? Maybe I didn't do it quite right, I dunno?? One of tbhe problems is the distributor connector has the 2 magnetic pickup lead wires and the 2 coil wires going thru it. Do they somehow need to feed back to the computer??
Thanks,
Ron

According to the schematic two wires (the solid black and the solid white wires in the schematic) connect the two magnetic pickup wires inside the distributor (yellow wire and green wire in photo) and go from the connector directly to the computer.

The other two wires that go thru the connector, go to the primary winding of the coil. The black w/ red tracer wire is a 12 volt (+) lead from the ignition switch to the positive side of the coil primary and also supplies 12 volts (+) to the igniter. The black wire w/ white tracer goes to the igniter and would be the momentary ground (-) connection for the coil every time the computer tells the igniter to fire (just like a set of points and condenser would). The igniter gets it's signal from the black wire w/ blue tracer and black wire w/ yellow tracer coming from the computer to the igniter.

It appears to me that you have two options with this setup. One is to rewire the stock coil to work with the MSD module, and the other option is to completely remove the stock coil and use the Nology ProFire coil you purchased. Either way the igniter will have to be bypassed and it's trigger signal from the computer also applied to the MSD module. 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 connecter.

Let me know which option you want to use and I'll help you figure out the connections to do it.

[rokan]

Awesome! Thank you for the schematic!
Here are some pics of the inside of my distributor.
Aaron,
I tried wiring it like you said and it won't start that way? Maybe I didn't do it quite right, I dunno?? One of tbhe problems is the distributor connector has the 2 magnetic pickup lead wires and the 2 coil wires going thru it. Do they somehow need to feed back to the computer??
Thanks,
Ron

[Gary Hammond]

Hi Ron,

I found a wiring diagram that claims to be for your vehicle. Maybe with Aaron's help, you can figure out how to wire everything up so it will work.

[Aaron Murakami]

Hi Aaron,



We must have both been posting at the same time. I didn't see your post until after mine appeared in the thread.

I understand what you're saying and acknowledge that you're correct. But the distributor on Ron's vehicle is different than most others, in that it has no external coil to rotor wire to hook up an external coil! It has a "built in coil" under the distributor cap. Is that how yours is as well? Here's a couple of photos of the system Ron must have.





The "internal coil" will have to be removed and a new connection made to the cap in order to hook a coil wire between the cap and an external coil. This will require some fabrication of new parts.

Ok, that's interesting - haven't seen that before. Didn't know what the multiple references were to the coil in the distributor. I wonder if they make aftermarket versions of these with coils that are intended be used with cap discharge.

Just saw Ron's post.

[Aaron Murakami]

MSD says "Solid core spark plug wires cannot be used with the 5520".
Aaron, will this interfere with our Plasma Ignition work?
Don't you recommend solid core wire for best performance with the Plasma Ignition?
Thanks.

Richard Gieser

The cables aren't that important for the plasma itself since the cap discharges across the spark plug gap and not through the entire cable.

However, since this method of plasma ignition is initiated with a CDI spark, it is a good idea to have cables that are suited for capacitive discharge.

[Aaron Murakami]

Originally I had the small red wire going to the ignition and had the problem so I switched it just to try but it made no difference? But the other wires may be wrong like you say? The way I had it wired originally was the way the guy at MSD told me to do it but he may not have completely understood what my ignition actually is? I will try rewiring it like you say Aaron and see if that makes any difference.

Thanks,
Ron

That is interesting MSD would say that because no matter the ignition, the small wire will always be the power switch wire no matter what. When 12+ positive goes to the small red wire, then the large red wire going to the battery is then connected to the circuit inside - probably thru some solid state relay or similar.

[rokan]

Hi Aaron,



We must have both been posting at the same time. I didn't see your post until after mine appeared in the thread.

I understand what you're saying and acknowledge that you're correct. But the distributor on Ron's vehicle is different than most others, in that it has no external coil to rotor wire to hook up an external coil! It has a "built in coil" under the distributor cap. Is that how yours is as well? Here's a couple of photos of the system Ron must have.





The "internal coil" will have to be removed and a new connection made to the cap in order to hook a coil wire between the cap and an external coil. This will require some fabrication of new parts.

Yes, that is my distributor. I modified the cap with a connector in the center to connect the external coil to the rotor and I disconnected the internal coil wires to connect to the external coil and MSD unit.

[Gary Hammond]

Hi Aaron,

Gary, did you see my post? ....................................

We must have both been posting at the same time. I didn't see your post until after mine appeared in the thread.

I understand what you're saying and acknowledge that you're correct. But the distributor on Ron's vehicle is different than most others, in that it has no external coil to rotor wire to hook up an external coil! It has a "built in coil" under the distributor cap. Is that how yours is as well? Here's a couple of photos of the system Ron must have.





The "internal coil" will have to be removed and a new connection made to the cap in order to hook a coil wire between the cap and an external coil. This will require some fabrication of new parts.

[Richard]

I'm guessing it would be I would double check directly with MSD though because I'm not familiar with that truck or engine. If the ignition coils has a simple + and - primary input with a single HV output that goes to a distributor cap, then it should work fine but please don't take my word for it.

Here is the instruction/data sheet for the street fire module with about half a dozen or more hookup situations. You can probably find your exact one in there and if so, should work fine. They're all pretty standard back then. https://www.jegs.com/InstallationIns...1/121-5520.pdf

MSD says "Solid core spark plug wires cannot be used with the 5520".
Aaron, will this interfere with our Plasma Ignition work?
Don't you recommend solid core wire for best performance with the Plasma Ignition?
Thanks.

Richard Gieser

[rokan]

Gary, did you see my post?

Ron has the white trigger wire which is for mechanical points and the red small wire, which is for the ignition switch positive to turn on the MSD going to the distributor instead of the violet/green wires. There is no way it can ever work correctly like that.

Igniters aren't the problem - I did it in my Subaru and it has an igniter and I did it with the wasted spark ignition on top of that, which some thought was impossible until I did it. Of course the way I invented to make it work on a wasted spark ignition coil pack system with isolated secondaries with opposite polarities on each end is a bit elaborate but is the solution.

In any case, I think the correct trigger wires on the msd has to be used and the small red wire needs to be on the + switch on the ignition or manual toggle switch to the + of the battery and it should work fine. Even if it doesn't wind up working, it has to be wired up correctly to begin with in order to assess what the deal is.

Originally I had the small red wire going to the ignition and had the problem so I switched it just to try but it made no difference? But the other wires may be wrong like you say? The way I had it wired originally was the way the guy at MSD told me to do it but he may not have completely understood what my ignition actually is? I will try rewiring it like you say Aaron and see if that makes any difference.

Thanks,
Ron

[Aaron Murakami]

Hi Ron,



I think you're right!

I did a little searching with google and see that your ignition system would be a real bear to modify. It has a fixed distributor and timing is controlled by the engine control module (computer). The trigger pickup is magnetic - appears to be a switched reluctance device with two rotating pieces. One piece is a finger and the other is a notched wheel. The two work together some way to give the trigger signal to the computer and then on to the "igniter". The "igniter" is a solid state device that amplifies the computer signal and switches the coil. And the coil is built into the distributor.

In order to use the MSD box and an external coil, the built in coil would have to be bypassed and electrically totally removed from the circuit. Then since the "igniter" is designed to drive the coil with a lot of current, it probably would be difficult to adapt it to only trigger the MSD box. I also found that a weak or failing "igniter" can cause the symptoms you described even with the stock ignition system.

Gary, did you see my post?

Ron has the white trigger wire which is for mechanical points and the red small wire, which is for the ignition switch positive to turn on the MSD going to the distributor instead of the violet/green wires. There is no way it can ever work correctly like that.

Igniters aren't the problem - I did it in my Subaru and it has an igniter and I did it with the wasted spark ignition on top of that, which some thought was impossible until I did it. Of course the way I invented to make it work on a wasted spark ignition coil pack system with isolated secondaries with opposite polarities on each end is a bit elaborate but is the solution.

In any case, I think the correct trigger wires on the msd has to be used and the small red wire needs to be on the + switch on the ignition or manual toggle switch to the + of the battery and it should work fine. Even if it doesn't wind up working, it has to be wired up correctly to begin with in order to assess what the deal is.