Hey Edgar, no problem. Keep us posted on the results.

:) sorry i'm not really online much anymore. But right now i'm not doing the direct fire yet, i just had an ignitor go bad so i went with the HEI to the leading just couldn't remember how to hook it up.

thought id update my TFIDFIS other than the TFI part lol. I have ran into two problems since doing this mod. I burnt up the trailing HEI ignitor. Oh well on that. And the connections have corroded slightly and the connectors have started to become loose. No problem but for a lill while i was scratching my head like WTF. But all in all Its dam good. Also i was able to upgrade to MSD Blaster 2 coils. I got them for free and that did help a lill.

Where are your HEIs mounted? They would best work where vibration is less. Mine
are on the shock tower, where the old SA ignition box used to be. Also make sure
the wires going to it don't transmit engine vibrations, thats probably whats
loosening your connections. I have mine anchored to the strut tower brace coming
across over the dizzy. That way theres not movement in the wires no matter
how much the engine rocks around.

If you drive in a lot of nasty weather and get water up under there make sure to
wrap or cover everything to it can't get water and salt and gunk sprayed up there
to cause corrosion. Of course your in Maryland and if thats near the ocean it could
be the good old salt air causing your problems.

Glad to hear back that its all working even with the glitches.

I have mine mounted to the tower also. On the side that faces the battery. I dont have the wires secured as you do. They wernt corroded just loose. Im hoping to get this mod done to another forum member soon also. As im plannin on switching to a CAS and second get coils. Ill be using a MSII. Im gonna be goin fuel injected soon. Least i hope soon lol. But till then she works very well

I've decided to do this to my FB. I went to the junkyard (LKQ in Clayton, NC) this afternoon to look for parts and came back with a few parts and a few questions.

My trailing ignitor has been dead for the past year, so I figured I would put the leading ignitor in its place, then do this GM HEI/Ford TFI setup on the leading plugs. Well I couldn't find any TFI coils that were worth a damn. All the ones from F150's were either broken or already gone...the rest were on Ranger pickups. I pulled a few off and every one of them tested under 8 kOhms on the secondary and over 1 Ohm on the primary...not to mention they looked like death.

I did find GM HEI modules though, but didn't bring the right size wrench for some GM distributor caps (needed 1/4" nut driver or something). I was able to snag two anyway....one was a 7-pin, the other is an unconventional looking 4-pin module (with a heatsink plate) that I'm not sure is going to work. Only paid $5 each for them because they thought they were some kind of relay/sensor.

Not sure what to do about the coils at this point...maybe break down and buy some MSD replacements off ebay.

Here is a picture of the two ignition modules that I got. Do, you think this 4-pin will work? I made sure I got the connect too.

https://www.rx7club.com/attachment.p...1&d=1300998614

I think I'm just going say screw it and go back to the junkyard (with the correct nut-driver this time) and yank a few more 7-pin ignition control modules. Still doubt I will find any coils, but you can find replacement coils on rockauto.com for $17 each...or high performance ones on Summit racing for $27. I did however also find out that the coils were used on some other vehicles (like the MX-6)...so I will keep my eye out for those too.

Here is the cross reference list of years/makes that used the TFI coils from rockauto.com

FORD (1982 - 1997)
LINCOLN (1984 - 1994)
MAZDA (1994 - 1997)
MERCURY (1982 - 1995)
MERKUR (1985 - 1989)

Yeah, any v8 Ford/Mercury/Lincoln using a TFI coil will probably work for you. The 7
pin HEIs should work fine for you. In fact thats what I started with originally. Just
make sure you ground the HEI properly as I found out and mentioned in the thread.

Keep us posted on how it works out for you.

Finished my setup last night. I ended up finding good coils on a couple of 94-97 Mazda 626's and great condition HEI Modules in early 90's Cadillac's.

Everything worked first try...both Leading and Trailing are firing. However, my tach still doesn't work...I was really hoping this would fix that as well as the trailing not firing problem.

Before I post all my pictures, here is my setup.

Leading:
-(2) Ford TFI Coils
-(2) GM HEI Ignition Control Modules
-Gutted Stock J109 Ignitor for signal

Trailing:
-Stock J109 Ignitor
-Stock Coil

Other:
-NGK BUR9EQ Plugs (All the way around)
-Magnecore 8.5mm Spark Plug Wires

Before

https://www.rx7club.com/attachment.p...1&d=1301327604

The Parts (had an extra HEI module)

https://www.rx7club.com/attachment.p...1&d=1301327604

Coils/Modules Mounted

https://www.rx7club.com/attachment.p...1&d=1301327604

Gutted J109 Ignitor

https://www.rx7club.com/attachment.p...1&d=1301327604

FINISHED

https://lh6.googleusercontent.com/_y...0/DSC_0945.JPG

https://www.rx7club.com/attachment.p...1&d=1301327604

Did the metal mounting brackets come with the coils? Also rather than gutting the J109 couldn't you just run a wire straight from the dizzy to the GM control module?

Yes those metal brackets came with the coils from the Mazda 626.

The reason for this mod was because my trailing ignitor was bad. So I moved the good leading ignitor to the trailing position and gutted the bad trailing ignitor for the DLIDFIS setup. But yes...you could have just connected straight to the dizzy.

Awesome! Thanks

Thats great to see you using the 7 pin HEI with no issues.

I had switched to new 4 pins on my initial build because of unrelated issues and
always meant to go back and put in the 7 pins to verify they would work as well.

Thanks for posting up in here with the pics and all. It really adds value to this thread
and confirms that I've helped my rotor buds in some small way.

Yea...it really drives great now...no more mid throttle stumble. Also I think it make have "fixed" my tach...it just hasn't worked in so long that it is sticking badly. Last night it didn't move at all...today it got to 900 rpm and stopped, but wiggles a bit when revved. Maybe it will work itself out.

Maybe I'll see you at one of the Raleigh rx7 meets. I sometimes come over there and
hit the meets or the bbq if I remember :)

Yea sounds good man. I have only been to a couple of the southern states mazda meetups tand need to go to more

Heres some updated pics of what I did. Its been running fine now since I started this
thread.

This is a top shot of the TFI coils mounted off my shock tower top.

https://lh4.googleusercontent.com/-X...0/SAM_0022.JPG

Another shot showing the connector to one of the coils.

https://lh3.googleusercontent.com/-H...0/SAM_0028.JPG

And last is the best shot I could get of the mounted HEIs where the SA ignition box
use to live.

https://lh6.googleusercontent.com/-b...0/SAM_0024.JPG

I got my parts and I'm ready to start building my setup. I'm using all new aftermarket parts. Updates soon.

How about posting up exact part numbers, prices and such as extra info in this thread?

Are you going with 4 or 7 pin HEIs?

Make sure to take a few pics as well. Good luck with the project.

Yeah what he said! I was slowly collecting parts to do this to my 83 until I had a coolant seal crap out on me. Now I've got coolant in bad places lol. I look forward to seeing your setup as it seems everyone does it a lil differently.

Update
 

I rewired the hot side for the HEIs and the coils to be relayed which is triggered
by the black/white leads from the engine harness. I noticed a few things right off
the bat on startup:

1. Raspier note from the engine

2. A bit better/smoother rev

3. My tach noise between 6500 and 8000 rpm is gone.

That tach noise bothered me but the engine always sounded smooth, so I was
pretty sure it was some sort of noise issue in the wiring harness. Probably some
weak connection to ground or something somewhere. Anyway, its nice to see
it gone and was totally unexpected.

I think getting the ignitor/coil power directly from the battery has really helped a
lot. It bypasses all that old wiring up thru the ignition switch and back. Why didn't
I do this at first? Just keeping it simple I guess or stoopid :lol:

I also relocated the TFI coils to mount using the stock coil mounts with some minor
tweaks to the upper part. This forced me to move my prop rod to the passenger
side as well. I'll get pictures up later.

Interesting......can you post a diagram of how you did the relay setup? Interested in incorporating it into mine.

Barron

Pics of TFI coils in stock mounting
 

Heres the pictures of how I mounted the TFI coils in the stock location. I just did
creative medal bending on the top of the coil mount bracket to shape it like this:

https://lh5.googleusercontent.com/-M...0/SAM_0373.JPG

I then painted them up real nice and mounted the coils with the modified bracket.

From the top:

https://lh3.googleusercontent.com/-7...0/SAM_0375.JPG

From the passenger side:

https://lh4.googleusercontent.com/-g...0/SAM_0376.JPG

I had to make some new wires as well because it was a bit of stretch for the old
ones.

Its pretty simple. I just used a standard 30 amp relay. I wired positive from the
battery to the 30 terminal and the hot side of the igniters and coils were connected
to 87. I then wired the BW ignition wire to 85 and put 86 to ground.

I think thats how I did it :scratch:

Anyway, I verified that when the ignition was on that I saw +12 volts
on 87 and when it was off I made sure to see 0 volts as well. Its just a switch
after all. Theres lots of info on the web for hooking up accessories with a relays.

Yeah, if you wouldn't mind putting together an updated wiring diagram for us I would be VERY grateful. I've long had this on my to do list as I work towards completing the restoration of Gus. I am interested in the raspier exhaust note you mentioned, and particularly the smoother revving. I used a 2GCDFIS setup in the past, but it felt kind of choppy to me, or hesitant almost. Like it didn't really want to rev up, but did it because it didn't want to disappoint me. :rofl: I'm definitely going to try this TFIDFIS setup. So, if you could throw together an updated wiring diagram in paint and post it that would be awesome.