t_g_farrell

iTrader: (1)

Yeah thats right, its a TFI coil based DFIS using the HEI modules for the
ignitors. My 2GDFIS has crapped out on me and I thought I'd look into a
different solution and one you can easily put together from scrounging
junkyards.

What you'll need:

2 TFI coils
2 new boots and crimped ends for the coil end of the plug wires
3 4 pin HEI modules
1 plate to mount the HEI modules on
1 tube of heat sink paste (Radio Shack??)
an assortment of connectors mostly female 1/4" spade connectors
some wire (red,black,green) 12 guage is good

I'm just starting on this tomorrow. Dropping by pullapart to pick up the goods
in the morning. Taking my DVM with me to ohm out the coils to make sure I get
some decent ones. The primary should be < 1 ohm and the secondary should
be somewhere between 6K ohm and 30K ohm. I'll drop by oriellys to have
them test the HEI modules I get to make sure they are good. I'll probably
grab more than I need to make sure I have some good ones.

I'll post pics of what I'm doing as it goes along and keep this thread updated.
Theres really not much to write up about this except show how to wire it up
and maybe mounting things. I think I can use the old base plate that the
J105s were mounted on for a 3 HEIs. I'll be reusing the pigtail that brings
the distributor induction signals into the old ignition box. Just some new
connectors. Biggest challenge will be mounting the TFI coils and reworking
the coil end of the spark plug wires to mate up the new coils.

Heres a diagram of wiring it up (I think):

installer67

iTrader: (18)

Cool! Let us know how it works out. If the performance is as good as your previous ignition setup, etc.

Stevan

iTrader: (17)

I like it, cheap at the j-yard.

t_g_farrell

iTrader: (1)

Got my 2 TFI colis and some 7 pin HEI modules at big discount all
for $25.01 grand total, out the door. The 7 pins are easy to find but the
4 pins are pretty rare it seems. I think the 7 pins will work fine I just
won't use a few of em

I won't be able to work on this until middle of the week. So hang in there
and I'll get pics and more definitive wiring diagrams done. The one I posted
is ok but it needs details like the exiting harness wiring added and the tach
signal.

trochoid

iTrader: (6)

Since I'm basically ignition system dumb, what's a TFI coil and what makes it different/better?

rxtasy3

iTrader: (2)

just a wild guess but i think the TFI coils r those off the late models that use a coil per plug?

Jeezus

iTrader: (4)

Tim, you still run the stock ignition? I believe you would have points (can't remember if you went
to electronic or not), and this would make a great upgrade. When I went to direct fire, it made a
world of a difference when I started. Car would start in 2 revs or less

Keep us updated!

diabolical1

iTrader: (3)

+1

Hades12

+2


I got no clue myself.

irishpilot

iTrader: (4)

excellent diagram...I wish I could find a definitive one for the FC coil setup...LOL... I havent read all the threads but most seem to be different in regarding to wiring.

Stevan

iTrader: (17)

TFI = THICK FILM INTEGRATED.
This is quoted from jeep forum, so...
{The TFI coil is Motorcraft's answer to the GM HEI coil, and out preforms the common GM HEI coil by about 1-1/2 times.}

They are plentiful, and cheap at the junkyards.
I used one w/the hei module on my 83 f-150 for a bit, gets rid of the duraspark ign module, and is supposedly higher output than the stock 83 coil.
The inline 6 jeep guys use the ford dizzy,TFI coil, and GM hei modules for a stand alone hei ign sys. I went to the original motorcraft duraspark ignition module(which I didn't have prior) because it retards the timing for better hot starting.

t_g_farrell

iTrader: (1)

Stock ignition on an 80 SA is electronic. I was running the 2GDFIS but I
think the ignitors, coil or the electonics behind the ignitors went bad. So I
decided to try doing this since I've always been curious about using the HEI
modules to replace the ignitors.

t_g_farrell

iTrader: (1)

I actually got inspired to do this after modding my neices 89 Jeep Grand
Wagoneer to use the Ford TFI coil and HEI dizzy cap and wires to upgrade
the ignition. Jeep guys do this on a routine basis. Heres a lin for one way
to do it: http://fsjeep.homestead.com/TFI_Upgade.html

Each TFI coil can put out about 30Kv for each spark. The older HEI modules were
only good up to about 5 or 6000 rpms but the newer and replacement ones
easily go higher. Since folks here have done the HEI swap with success, I
feel like the only unknown here is the TFI coil. I'm not sure if my 2G coil is bad
but if I go this route, I can source a replacement very easily whereas finding
a 2G coil could be hard sometimes.

That wiring diagram is by no means complete or correct but it gets the idea
across. I will be digging into my SA electrical diagrams and updating it with
well defined connections points referencing OEM wire by color and connector
this week. I plan on getting the wiring diagram done right before I do any
actual wiring. Should make the job a peice of cake when I do the implementation.

The hardest part is figuring out where and how I want to mount these 2 coils
up. I also want to get the HEI modules tested and see if I can test the coils
to make sure I have good components.

t_g_farrell

iTrader: (1)

What he said

rare70cat

iTrader: (2)

Why not go the ford route and have the coil at the end of the plug boot. I have been wanting to due this also. In fact I put up a post a while ago to see if I could get some help.I also have the 2GDFIS. With the coils at the plug boot you don"t have to worry about a mounting location and looks pretty cool. I didn't know if I needed a third igniter. I thought I could just run the wires from the ignitor in parallel to each coil. Would this work? Thanks for any ideas/input. Rob

rare70cat

iTrader: (2)

Isn't the 2GDFIS run in parallel? One ignitor feeding the leading two coils. and one ignitor feeding the trailing coil.

rare70cat

iTrader: (2)

Your diagram you say is not correct or complete but thats exactly what I'm talking about except no hei modules but having a coil per plug setup. I guess the big thing is getting rid of the expensive J109s.Right?

t_g_farrell

iTrader: (1)

rare70cat, I think you would have to come up with a way to mount the coil on
plug setup so that it addressed the shaking it will get hanging off the
rotary plugs. Most coil on plug setups I've seen use a deep recess into the
valve covers which helps support the heavy coil as its plugged into the spark
plugs. Coil on plug would be cool, don't get me wrong but I don't think it would
be a simple setup and easy to install setup.

In my setup I'm opting to use an HEI module for each coil as gsl-se addict pointed out that a single HEI might get too hot to drive 2 TFI coils. The 2G coil is designed to
be driven by a single ignitor although it may have stressed my j105 ignitor in the
process.

My diagram is not complete as its missing the link for switched power on the
coils and exact routing of connections to whats left of the stock wiring harness.

t_g_farrell

iTrader: (1)

So originally I was going to use the 4 pin HEI modules but since they
were almost non-existent in the pullapart I went with the 7 pin HEI
module type 5 + 2.

I wasn't sure if I could use it but after doing some research it looks like
it should work fine. The extra pins are there to allow an ECM to bypass
the reluctor timing signal and supply ECM sourced timing.

In our case we will not hook up those pins and the module will basically
act like a 4 pin HEI module. The pins E, R, and B will not be used. These
pins allow the ECM to get the tach signal as a square wave (R), bypass
the reluctor timing signal (B) and supply the ECM timing signal (E). By
not connecting these pins the module runs at it base timing which is
whatever the ditributor decides using its vacuum and mechanical
advances.

One advantage with the 7 pins modules is that they supposedly can
handle more amps. The OEM 4 pins are limited to 5 amps whereas the 7
pins go up to 7 amps.

So heres what an HEI 7 pin module looks like:



And this is the internal schematic I found for it:

t_g_farrell

iTrader: (1)

I also updated the original wiring diagram for using the 7 pin HEI. Note I have not
shown the OEM wire harness connections yet that will come in a bit.

t_g_farrell

iTrader: (1)

Heres the latest wiring diagram with OEM wire color codes added. The 6 pin
connector I show is not documented in any wiring diagrams but it down
low on the shock tower and it is a pigtail that connects the 80 ignition box
with the distributor harnes that snakes down below the distributor, under
the AC and over to the shock tower. On mail side only 4 pins are used with
each being green and red. One set for each reluctor. On the female the
wires are color coded red and blue for the leading and white and black for
the trailing. The other 2 pins are connected to the sheilding on the pigtail.

Now I'm off to build a nice harness for all of this.

Heres the latest diagram:

t_g_farrell

iTrader: (1)

Ok, I'm about to head out to the parts store to gather up some
materials to build this up today. I'll also be getting my HEI modules
tested to make sure I have some good one. I'll be taking pics
as I go along and will post them up when I'm done.

t_g_farrell

iTrader: (1)

Got it all wired up but I need to make new plugs wires. I bought an accel
red 8mm spiral set that I'll replace my RB ones with.

Heres a teaser pic, more pics and write up to follow, maybe tomorrow.

t_g_farrell

iTrader: (1)

I haven't finished debugging the setup yet, although it did start right off
the bat. Which is good news. Bad news is that the leading colis are not
firing, I'll have to dive into that next. Might be bad coils from the JY or
wiring issue (as in I screwed it up in some way). Since the trailing coil
is firing correctly I know my basic wiring design is right for the HEI 7
pin module and it appears to work fine.

I got all these parts at the pullapart eher in Charlotte. The HEI came
off of late 80s or early 90s GM v8s. The TFI coils both came off of F150
pickups.

I tried to grab the HEIs that look like they had the least abuse from heat
soak as they live in the dizzys and take a beating from the heat of the
cap mounted coil and the engine heat. A lot of times the plastic connectors
just crumbled off. I skipped those modules. I also tried to stay with the
OEM GM parts as they are known to be of better quality than the aftermarket.
BTW, these 7 pin HEI cost a bit about the sameas the 4 pin modules.
I took 4 of the HEI modules home with me and then went to Oriellys and
tested them on their tester. They all tested good. They get pretty warm when
being tested too.

I took my DVM with me and tested the primary and secondary
resistance of the coilds to hopefully grab good ones (although now
I have mydoubts). The primary (between the two connectors) should
be < 1ohm of resistance and the secondary (using one of the connectors
and the dizzy post connection) should be 8 to 30 Komh. Quite a range
but that the best clues I had.

So here are parts I gathered the other day (left to right, top to
bottom):

2 TFI coils and pigtails
Aluminium mounting plate from old igniter box
3 good HEI 7 pin type 5 + 2 modules



I reused the aluminium mounting plate from the old ignitor box to mount
the 3 HEI modules on. I mounted the trailing HEI on the back and the 2
leading HEI modules on the front. I made sure to use a good coating of
heat sink paste I got at radio shlock. I drilled and tapped some holes
for the HEIs and mounted them.

Heres the front view:



Note the heat sink paste in the pics. Very important to use that or you
will fry your HEIs.
Back view:



and top down view:



Next mounting the coils up.

t_g_farrell

iTrader: (1)

For the coils I bought some aluminium angle stock at Lowes. I think it's 3/16 thick,
pretty stout stuff. Not too hard to cut up either. I cut and drilled them to place
the coils side by side up next to the brake MC, hanging off of the shock tower
strut bolts. Its pretty sturdy and doesn't jiggle or wobble around. If I need to
I can add a support from underneath to brace it against the lower part of the
shock tower but it seems to hold well as it is. I was able to put almost my
full weight on it and it didn't budge. I had to trim out some openings for the
coil plug access on the inboard mounting rail.

Heres what I came up with:



Here are both pieces mocked up in the bay:



I then had to cut and run my wires and then loom them up to keep it
neat. I may add a relay to provide the +12 v to the HEI and coils but
right now I'm just taking it off of the existing coil. I'm using the old leading
coil as my trailing coil now, that keeps the wires a bit shorter.

Heres some picks of the finished install: