Jeff20B

Darn, I have a NPN 2N3055 transistor. I once used it in some ignition experiments a few years ago. It started getting hot because it wasn't screwed to a heat sink, but I didn't run it for too long anyway. So, what do you think?

83turbo

To use an NPN:

Emitter goes to ground.

Collector goes to '86 ignitor red wire and to a 1k resistor to +12v

Base goes to J109 ignitor output and to a 1k resistor to +12v

Jeff20B

Thanks for the wiring info. Are you saying I still will need a J-109 ignitor? Or will the resistor and transistor help switch the 2nd gen leading ignitor just fine?



I'm trying to find an economical way to use the leading ignitor on a trailing coil. If I can't, I may need to buy a GM HEI ignitor. I'd prefer not to though.

83turbo

Yes - the J109 is still needed to provide the long dwell signal.

The '86 ignitor is much more powerful than a GM HEI.



The _trail_ ignitor, on the other hand, has automatic dwell control, and is

just as powerful as the lead.

Jeff20B

Ah, maybe I can use my trailing ignitor instead. If only I could figure out the wiring. Do you think it would cause any long-term damage to only use one circuit of the trailing coil instead of both? I'd imagine it'd run a little cooler.



If I didn't have an MSD, I'd use one J-109 and the 2nd gen leading ignitor on the leading coil, like you mentioned.

83turbo

On the trailing ignitor:

Red wire is the trigger

There is a white wire next to it that selects which coil you are firing.

The other 2 wires are tach and "status" to tell the ECU the coil fired (ECU gives a

fault code for bad trailing coil)

The other 2 pin connector is of course for power, case is ground.



Shouldn't be any problem just using one side. (And you've got a spare built in!)

The trail ignitor is just as powerful as the leading.

Jeff20B

That's cool! I think I'll just cover the two unused coil connectors so they won't ground on anything or contact each other. I'll also remount the trailing and leading coils onto their bases. That's great because it means I won't need to fab any coil holders, unless I've got a small amount of room to work with (I won't know until I actually try to mount them). I'll leave the leading ignitor in its base for future use and just cover all the connectors so they won't interfer with the MSD's black and orange (coil) wires.



I wonder if I could connect the leading pickup to the leading ignitor in a pinch? You know, like if the MSD dies on me out in BFE?



Sorry to ask so many questions. I wish I could concentrate fully on this 2nd gen coil stuff. My free time is taken up by a 20B.

83turbo

Looks like the distributor will trigger the trail the same as it

triggers the lead. Check with a timing light, though - make sure it's

doing what it's supposed to.

Yes - you should be able to use the lead as a backup. I was having some

problems with it at low RPM (below idle RPM). Mazda has used two

different style reluctors though. Maybe the other one works better

for this application. (They sort of look like enantiomers (mirror image)

of each other)).

Jeff20B

I'm familier with the '80-only and '81-'85 style. They looks lsightly different, but both have a slow rising rate and then a fast drop-off. It produces what I call 'lopsided AC'. This is of course just a guess, but I bet if you observed the wave form on a scope, it would sorta look like a lopsided sine wave. Or better yet, kinda like a heart beat. It's even enough to light up an LED for a split second.



Ok, I'm going to try wiring the trailing ignitor to a pickup that's sitting outside of a distributor (long story). A screwdriver pulled from it quickly is enough to trigger a J-109 (or flash an LED), so I'll see how it does with 2nd gen ignitors.

Jeff20B

I got it to work somewhat. It seems the reason why I got this for free with a missing T1 coil is because C2 (blue wire) doesn't seem to work. I hooked up a Hanshin coil on C1 and got it to spark randomly. I tried the pickup and a speaker (have you read my fun way to test ignitors and coils?). Same results; it sparks randomly. Then I swapped the C wires and now C1 is on coil T2 and it finally sparks, but still randomly. The Hanshin on C1 no longer sparks.



The guy I got it from must have assumed a coil went bad, but in reality, the ignitor seems to have gone bad. The T2 coil works great on the MSD, so we know the coil definetly still works.



Is there a way to trick the ignitor into firing C1 every time it gets a trigger signal? Speaking of trigger signal, it's as if it needs a more powerful trigger to spark the coil than a J-109 or the MSD. Why is that? Is it because one side of the trigger is grounded? It seems to me it will not reliably trigger at low RPM, as you've also discovered. If it's below cranking RPM, that's probably ok.



I'll tell you how I wired everything in hopes you can recreate what I've done:



green pickup wire to red ignitor wire

red pickup wire to ground

brown (tan) wires to + of both coils and battery +

C1 to - of any kettering coil (whatever)

C2 to - of T2 coil

aluminum base to battery -

high tension outputs of both coils to two vice grips or locking pliers grounded to battery/aluminum base



I think that's it. Let me know what you come up with.