BlaCkPlaGUE

SO i was checking out my coils today, and just for kicks I decided to take them apart and see what they're all about.
AFter taking them apart, and realizing that there really isn't much to them at all! I saw a couple of things that concerned me.

(Mazdatrix Image)
If you look at the above, you can see the stock coil packs. The four screw holes that are pictured have metal plating on the inside where the screw goes in, and the backside where the screw comes out. The backside metal makes contact with the four points on the igniter assembly in wich the screws mate up.

Do both of these points within the four screw holes require conductivity? Cause when I looked at mine, the metal on both sides was corroded with lime, oxidization and on the bottom of the coil pack wich lines up with the ignitor, rust.
If this is the case, the coils performance would be shot huh?

Another reason that I ask is becuase Im working on a coil restoration that involves paint and the like, and if im going to paint/powdercoat the igniter assembly, do I have to leave the tips of the ignitors (4) conductive? Or can I just paint the tips along with the rest?

Final question. Im sure this is an issue, but im going to ask anyways. The +/- wires that lead to the coil packs from the igniter assembly are attached to washers that bolt up to the coil. When I took them off, the washers and all surfaces seemed to be oxidized, would this affect performance as well?

If all these things affect performance, im gonna make a writeup on coil restoration since its so easy and I like doin that ****. Detailed images/instructions to be included.

thx for your time.

BlaCkPlaGUE

ah yes, I almost forgot. But does the base where the ignitor attaches to the chasis of the vehicle require conductivity as well for grounding purposes? the brass or whatever it was seemed to be oxidized/corroded with ****.

I mentioned performance as well, what I meant to say was 'coil' performance and not engine performance

NZConvertible

The coils have two little wires from the ignitor and two big wires to the spark plugs. That's all the connections they need, the screws do nothing.

The wiring diagram does not indicate the ignitors being grounded to the chassic. The operate similar to the injectors, they're fed 12V from the main relay and the ECU provides a switched ground.

Any wire connections (like where the the ignitor wires connect to the coils) should be clean and free of rust, dirt or paint.

Hope that helps.

BlaCkPlaGUE

Thanks man! That answered all of my questions!

BlaCkPlaGUE

While we're on topic, what exactly is the relationship of the ignitor and the coil?

NZConvertible

The ignitors control the charging and discharging (firing) of the coils. The ECU tells the ignitors when to fire the coils.

Icemark

As Jason said, the coils will fire regardless of being bolted to the body, the only reason for the conductivity to the body is for reduction of electronic noise (in the stereo, ECU, etc) by grounding the sheilding of the coils through their bodies.

HAILERS

My, my. Jason and Icemark both wrong in the same post. Congratulations to both of you. Did you collaborate on this????? Full moon??? You both need to get out of the house and work on your cars more often. Mainly in th e coil area.

EDIT: That written above probably wasn't too clear to you two. Do this. Unbolt your Lead coil assy and rest it on a rag or piece of wood. Go start your car. Question: how well does your car run with only the Trail coils working? Mine does not run very well the last time I did that.....years ago.

Icemark

actually mine is mounted on plastic spacers so that the coil body does not ground at all and it runs just fine...

perhaps you are confusing the coil with the battery... I know they are mounted in the same area

HAILERS

It grieves me very much to tell you, that the METAL bolts/screws that are holding your coil/ignitor assy in place on those spacers.......will carry electrical current.

There's an old saw *If you find yourself in a hole, stop digging*. You might take that into consideration before replying.

jl1rx7

iTrader: (1)

wouldn't the coil packs put all there discharge into the chassis, if the mount bolts conducted? yes of course they will conduct eletricity since metal provides path of least resistance, and cleaning the crap off the bolts wont help the function of the coils it might help cut down on the electric noise created by the coils firing

HAILERS

I'd suggest the above go out to their car with a ratchet and a 10mm socket and unbolt the Lead coil assy and place it on a rag. Then start your car............using only the trail coil assy, because the Lead won't fire because the ignitor circuit uses the ignitor body as a ground.

Read the post above where it says *When you find yourself in a hole, stop digging*. Take it to heat.

BlaCkPlaGUE

LMAO hailers, icemark, nz, you guys are too funny when in disagreement.

Hailers, you said the screws carry electrical current, so are you saying that its important for that part of the coil assembly to be conductive?

help me out.

Icemark

I'll go shoot a little .AVI and show you...

then we will see who is digging the hole...

HAILERS

The electronics in the ignitor have to switch to ground. Now go look at the diagram for the coil assy's and show me where the place is that it switches to GROUND. It's the body of the coil assy. Always has been, always will be.

You've four studs and nuts providing the ignitor to ground path. One will do. Been there, done that.

Or put it like this: you've got the Trigger signal coming in from the ECU. Now it's going to switch *something* in the ignitor to GROUND. There ain't no other wire that leads to ground.

I learned this by accident several years ago when I had two Lead coil/ignitors rigged. One for the front rotor, one for the rear. While rigging the wiring I had the second Lead coil assy sitting on a rag on the fender. Couldn't figure out why my rear Lead coil wasn't firing........til I put a ground on the base. Then it fired just fine and dandy. FYI: The car ran just fine and dandy using two coil assy (one front, one rear lead) but then again it wan't running any better either.

P.S. I like using words like *ain't no other*. I do it on purpose. Much like clowns don't know how to use the CAPITAL KEY on their keyboard (twits all).

By the way, this morning I went out to my 87 and spent ten minutes unbolting the Lead coil assy and setting it alternatly on the fender and then the studs with a timing light on the lead wires. TRUST me, the base of the assy is the ground path for the ignitor electronics. I thought EVERYONE knew that. All this time I thought I was the last to know. Tsk, tsk.

NZConvertible

Well I might have to side with Hailers on this one and admit I was mistaken. The FC wiring diagrams don’t indicate the coils being grounded but the FD wiring diagrams do, and the ignition system are configured very similarly. The FD schematic shows a bit of internal detail of the ignitor, including the transistors which have positive triggers from the ECU, not the switched grounds like I thought.

BlaCkPlaGUE

When I was taking apart the coil assembly, there was a ground wire with a black tip connection coming out of the ignitor assembly. I always thought that was the ground.

HAILERS

That's the rpm diagnostic check connector. NEVER ground that item. Same with the one on the trail coil assy.

BlaCkPlaGUE

My electrical knowledge is utter ****, thank you for telling me that. I checked the wire and followed it and it pretty much goes right up to the - on the coil pack, I figured that was a ground. lol.