Ilum

I tried searching though the various threads on this mod and I didn't see anyone else having these types problems. Here is what I have done:

1) Received 2nd Gen Leading Coil from eBay purchase
2) Removed 2nd Gen Ignitor
3) Connected Ballast resistor to ground as per instructions.
4) Moved wires from original leading coil to 2nd Gen coil paying attention to polarity.
5) Moved leading spark plug wires from distibutor cap to 2nd gen coil.
6) Moved trailing spark plug wires and coil wire to leading positions on distributor cap.
7) Check all wires for correct/good connections.
8) Start car and watch engine idle horribly for about 30 seconds before stalling.

Could this be a bad 2nd gen coil? I have tried pulling the wires out of the 2nd gen coil (not at the same time) and pulling L1 makes it run worse, and pulling L2 kills it completely. I am not sure how else I can describe this.

Does anyone have any ideas of what I could try or what this might be? Do I need to adjust the timing or something?

85 FB

You messed up with the ignition wires. I'm not sure what How-To thread you read, but they never said to switch up the coil wires like you described.

You take your Leading spark plugs and lead them to the respective ports on the 2nd Gen Leading coil. Everything else you leave alone, ignition wire wise.

Ilum

I followed this one: https://www.rx7club.com/showthread.p...hreadid=243350

'85GSL-SE

iTrader: (2)

Something went wrong evidently. It sounds like your motor is now only running on the Trailing plugs alone. Can you take some detailed pictures of every step of your setup please. That would aid in figuring out your problem. But all in all I did the same as you posted above and mine works above expectations.

Perhaps the coil itself is bad? I do not know but it sounds like you installed it correctly hence why the detailed pictures would be a great Plus to visualy verify the accuracy of the install!

85 FB

I did the 2nd Gen ignition install. What you should do it get the wires for a 2nd Gen and use those to mate up better to the 2nd Gen coil. Lead the wires from the leading spark plugs to the ports in the 2nd Gen coil. Remove the coil wire leading from your old (stock) leading coil.

IIRC, that's how it was done.


Hopefully, gsl-se addict will see this thread and jump in and save the day.

Ilum

85GSL-SE:

I was wondering if it might be a bad coil too, but I don't want to rule out that it may have been something I missed. I'll take pictures when I get home and post them then. I havent' tried getting 2nd gen wires yet.


Thanks all for the suggestions, I know with help I can get this working.

85 FB

^ on the 2nd Gen wires: They'll fit in perfectly with the 2nd Gen coil. And, they'll have a longer reach for wherever you put the coil.

I'm not sure if the setup you did is the same as what I did. I just stuck in a 2nd Gen coil (redid the wiring inside as per instructions), rerouted the Leading spark plugs to the 2GC and removed the stock Leading coil wire.

And, I did reroute the wires from the stock Leading coil to the 2GC.

'85GSL-SE

iTrader: (2)

Oh yeah my man, post up some pictures and we will get you running in no time flat!

If everything does check out then you know it is an internal problem with the coil itself.

RX7 allnight

follow page 8 on the thread its super simple

https://www.rx7club.com/1st-generation-specific-1979-1985-18/easy-2nd-gen-direct-fire-install-20-minutes-243350/page8/

ray green

iTrader: (14)

I agree, the post listed above has the info but it still is a bit buried. After getting totally confused I just went out and put it in - I didn't have to change the 2nd gen coil pack around at all, if I wanted to I could remove it and put it back in a 2nd gen.

Here's what I did (from page 8 on https://www.rx7club.com/showthread.p...43350&page=8):

"OK, I went out and did it. I started about 10:30 and started it up at 11:15.

I took Kent’s lead and didn’t even open the ignitor housing and didn't cut any of the stock wiring on either the 2nd gen coil or my precious 1st gen ignition harness.

I just made two jumper wires with suitable ends to tie into the (-) and (+) on the stock leading coil then attached these to the 2nd gen coil, (-) to (-) and the (+) wire to the hole for the tan wire in the stock white plastic connector accoding to Kent's instructions. I was lucky to have a little red connector that fits tightly into the white plastic second gen connector so I didn't have to cut it off and make a splice.



I bolted the 2nd gen coil pack to a preexisting threaded hole and will add a second self tapping bolt tomorrow. All in all, a much simpler job than this post would suggest.

The car starts quickly and idles more smoothly than with the stock set up, I can feel the added horses wanting to get out. I’ll take it for a test drive tomorrow.

I'm still not clear on why the trailing plug wires should go to the leading connections on the distributor cap. I tried it both ways and it idles better with them set up this way, but it didn’t really make that much difference:



Since nobody seems to be able to offer a reasonable explanation, I guess I'll just try it both ways and see which gives me the best gas mileage."


Here's two videos, first without the dizzy cap on:


Then with the dizzy cap:


I have since found that it works fine (better because of direct contacts in the dizzy) with the trailing plug wires hooked to the leading outlets on the dizzy cap (thanks to Jeff for explaining why you use the leading dizzy connections for the trailing plugs):



Ray

85 FB

^ I still can't get over how clean Ray's engine bay is.

Rx-7Doctor

iTrader: (13)

The reasoning behind moving the trailing wires to the leading position on the cap is so that the spark does not have to jump as far. As far as a difference goes, who knows?

I do know that I got about 3 MPG increase with the 2nd gen coil vs the stock one.

yetterben

can you use these in the same manner instead of the 2nd gen coil

http://store.summitracing.com/partde...5&autoview=sku

So you basicaly just jumpered the - + from the leaing coil over to the 2nd gen coil. Dosnt that cause harm to the old coil?? not that its in use or anything??

MosesX605

I was going to say the same thing. Fantastic work, ray!

The engine bay of my racer is disgusting, between the seepage from the Webers and the leaking oil cooler lines.

ray green

iTrader: (14)

Thanks 85 FB, I know, I'm showing off again.

Don't know about the MSD, but yeah basically you just jumper + to + and - to -. The second stock coil is not in use, I just keep it there for a back up, it takes about one minute to switch it back over. So I would think just about any coil would work.

While we are on the subject, what about the trailing coils from the FC set up? Everyone specifies to use a leading coil but I have a pair of the trailing FC coils (they use two for some reason) and they look like pretty much the same thing.

Doc, anyone, know if so and if not, why?

Thanks
Ray

85 FB

So, from reading what The Doc has said, with my 2GC install, I can switch my trailing ignition wires to the leading ignition stumps on the dizzy cap?

bad 83

iTrader: (3)

Hey Ray, I know we have discussed this a million times, but the way you have yours wired is totally bypassing the second gen ignitor. With hooking the power to the coil (if you are not using the secong gen ignitor), just removed all the ingitor and wiring out of the case, and just have the coil there. If you are using the second gen ignitor, there is another way to wire that in.

gsl-se addict

iTrader: (3)

Sounds like the 2nd gen coil is either firing intermittently, not at all, or the plug wires aren't making good contact. The 1st gen wires can work, but they have a hard time reaching all the way into the 2nd gen coil post to make contact. Best bet is to use a timing light and see what is going on.

85_FB: your setup is a bit different since you followed my way of doing it to use the ballast resistor, but keep the 2nd gen ignitor in place for future use. This is really the way to do it. No need to cut the ignitor like most write-ups state. Yes, you can move the trailing wires over to leading (T=>L, T1=>L1, T2=>L2). This gives one less jump for the spark to make, plus looks a bit cleaner IMO.

Ray: The FC trailing is like this. It has 1 ignitor box and 2 coils. This is because you cannot fire the trailing at the same time. There is a signal from the 2nd gen ecu (called select) that tells the igntior whether to fire coil #1 or #2. If you remove the ignitor, the FC trailing is really two separate coils (like we have stock). In order to use the full FC ignition, one needs an ECU and a CAS (Crank Angle Sensor). The CAS is required to determine engine position.

Hope this helps. Take a couple detailed pics and we can tell you if everything is wired correctly.

Kent

85 FB

^ Thank you, Kent. That really helps.

ray green

iTrader: (14)

Yup Kent definitely has the right idea about keeping the 2nd gen ignitor in place and just bypassing it. Here's a picture inside:



And here is a close up of the wiring:



Notice the + connection hooks up to the tan wire, not the red wire, the one on the right in the white stock FC connector that I have my + lead connecting to:



And thanks Kent also for the explanation on the FC trailing coils, if anyone wants a set they are free for the shipping!

Ilum

Okay, I tried the mod again (I had already removed the ignitor before my first try at this) and I took pictures this time of how I have it wired. I did it very similar to Ray's setup except my engine bay is not nearly as clean. I am not sure what I did different this time other than leaving the trailing coil and plug wires in their original locations... but it worked. I have noticed the idle surges between 550 and 1000 rpm sometimes now, and it didn't do this before. I am going to keep an eye on it and my original coil wire in the glove box just in case. I have also noticed when it is not surging, the idle is very smooth. It was worth it for that alone.

Kent, you may be right, I may not have had the wires firmly seated in the coil. I am going to be looking at picking up some second gen wires and maybe plugs too.

Other than that, I can only think it was human error somehow. I did everything the same except moving the trailing coil and plug wires. I will try moving them tomorrow and see what happens. I would like to thank everyone that jumped in to offer advice and suggestions. I'll let you guys know tomorrow how it's going. Thanks again.

BTW, do let me know if I did do something wrong with the wiring, but since it is working I don't think that was the case...

gsl-se addict

iTrader: (3)

Looks good to me. The sparkplug wire probably aren't seating fully. It is really difficult to get the 1st gen wires all the way down those posts (unless the boot is moveable).

If you have a multimeter, you can see if you are making contact. With car off, unplug the leading wires from the sparkplugs, but not the pack. Measure resistance between the two sparkplug wire ends. If the resistance is about what the wires should be (like 20-30Kohm or whatever), you have connection at the coil. If it is showing out of range (with the scale on say 100k, or 400kOhm), then you do not have contact and need to push the wires in further.

bad 83

iTrader: (3)

I think I see a problem. You have a S5 leading coil. The negetive runs through the resistor. You need the positive to run through the resistor. Then your negetive signal from the J109 goes straight to the negitive on the coil. Kent, correct me if I am wrong on this. I never use the coil by itself. I always run it using the second gen ignitor.

gsl-se addict

iTrader: (3)

No. Doesn't matter. The resistor just should be in the circuit (either + or - side). As you said, Mazda wired both ways (some are on the tan side, some on black side). On the link that Ray posted, there is info that I posted on how one can use the 2nd gen pack (without using 2nd gen ignitor) without cutting any wires. There are 2 ways to do it depending on how your 2nd gen coil came wired from the factory.

Kentetsu

For what it's worth, I don't use the resistor anymore. Haven't for about a year, and haven't had any issues even during races. All I do is separate the coil from the ignitor housing, then move the + and - from the old coil straight to the new coil....