Poor Mans HEI

[shaggimo]

 I thought about doing the MUI upgrade, however, the motorcraft module (which seems to be a bad seed, from what I've read) is still in the system. I thought about just dropping an MSD box in and calling it a day, but, my 6AL I normally run in my malibu puked out a couple of weeks ago (not happy BTW). So what to do? I see it's possible to get a new (or reman) GM HEI distributor to drop in, but you need a special gear, plus it's kinda pricey. While searching the net for options for my malibu (stock doesn't cut it after having MSD), I stumbled on a link to "Junk Yard Genius", the name alone was intriguing, it posted "stealth HEI for jeep".  Basically, you take an old motorcraft duraspark module, gut it, saving only the pigtails and housing. You need a little diode, heat sink compound, a heat sink, some wire, and a GM 4 pin HEI module. I had a spare HEI module laying around, the diode and heat sink compound cost a tick under $5, the in-op duraspark module mailed to my door for less than $10 (Thanks simpson).
 So I printed out the directions along with the diagram to try this set up. Gathered all I needed, and here's what I did.
We all know what a stock box looks like, lol.

first step gut the module.

It's a royal pain but, there's a few different methods, I used map gas, burned and pryed it apart, haha. Should end up with this.

Use care with the pigtails, you need them, I got carried away with the torch and had to cut them shorter than I would have liked, here they are lengthened and ready for hook up.

This is the first attempt, that didn't go over so well, the spare module I had kicking around was a cheap Chinese junk aftermarket one  . If there's no name on it (GM, WELLS, etc) , then that means the company is too embarrassed of their product to own up to it, in other words it's junk don't use it!!

As you can see blank module wired in and fastened to my heat sink (1/4 steel plate, until I can scrounge up a chunk of aluminum or copper). That white ooze you see it the heat sink compound, the diode goes in the white wire that hooks in with the red wire, I ran the red directly to the spade, and then crimped the with to the reds' terminal (it was a double crimp type). The Orange and Violet wires MUST be twisted to gether and kept away from the red and white.

Assembled stealth module, I cut another groove in the ford box just to be certain the red/white stayed away from the violet/orange.

For the record I'm running an MSD Blaster 2 coil, mounted in the factory location, with the noise suppressor in the factory location as well.


The results, I tried to fire up the car, it fired instantly, then stalled, I tried again it ran like a top fuel dragster blump.......blump.......blump, I hit the gas and cahpoo (stupid nameless junk module). So being that my malibu is dead in the driveway with a bad starter/solenoid (royal pain to get to, BTW), I robbed the WELLS HEI module out of it (Old Reliable has been in every carbureted HEI vehicle I have had, haha). Took about five minutes to change the module out, put the box back in the factory location hooked up the wires, and the car fired up almost as quick as the starter engaged  , ran smooth as could be, throttle response seemed great. I took it out for a little test drive around the block, and the car ran better than it ever had for me, BTW I thought the Eagle ran good before, I was just leery on the motorcraft box. I don't know the long term part of this, or if it will last, or anything. The really good thing about this upgrade, is if you start with a good running duraspark setup, then remove it keep it in the car, go with the modified HEI set up, You have a back up ignition on hand if the HEI mod fails. Just plug the old back in, put the stock coil back on, and you're back to driving  , because no mods were made to the vehicle itself. Not to mention HEI modules are easy to find at any parts store, and there are plenty of HP versions as well.  All together this mod cost me $15, some spare parts (MSD coil is a spare for the malibu, haha), and a little more than a couple hours total.


So has anyone else tried this? How did it work for you?

[wagoneerhauler]

Thanks for posting this.  I wish I had known about it years ago.  Could have eliminated the cruddy stock system on our Jeep GW.  I think I'll give this a shot on the SX/4.

What is the web page where you found the original instructions?

[shaggimo]

Whoops, I forgot to post that, lol.
Here it is, very simple directions to boot.

http://www.junkyardgenius.com/ignition/jeep/HEI01.html


Like I said, I'm not sure about longevity, but I'm going to keep the stock box and coil in the glove box for a "just in case". I was going to wait until I had more info on life span to post this, but I noticed it had been mentioned before but didn't have any follow up, and I've noticed a sudden surge of others having module problems, lol.

[wagoneerhauler]

Great and thanks.  I must have had used maybe 3 or 4 (at the least) different modules during the 8-9 years we ran the grand wag.  Some being used but others new.

I have a stock pile of different heat sinks and if we meet up to work on the EG eagle collection I'm sure we can find one that would work well for ya.

[shaggimo]

Cool, sounds good thanks!

[IowaEagle]

Thanks for anothe solution and for the Rambler Mentality involved.

[mudkicker715]

Just for the record msd will fix there 6al or 6a for under $90. I called them about a year ago for a junk one I have. 
Your idea or find is much better however

[shaggimo]

I thought about shipping my msd box back to them to fix, but, I dunno I've heard lots of good about the DUI set ups, for the module and coil (comes with cap and rotor) it's something like $128 for a GM type.  I may try it on my malibu, if I like it, I could add the module to the Eagles modified box too the module is only $49.

[shaggimo]

A little follow up note to this ignition mod, I have put about 250 miles total on the Eagle since the swap, about 200 of them were this past weekend. Car ran great with the upgrade, no acting up what so ever ignition wise, very pleased. I will update every now and again for a while to prove its reliability, and also will keep track of fuel milage when all other bugs are worked out.

[IowaEagle]

That will be much appreciated.

[shaggimo]

Ok, so an update is due since I kept track of milage, first tank ran through the car: about 16 mpg, but keep in mind this car sat dormant for 15 years before I awoke it last year, also car had a weak pressure plate (clutch was slipping a bit). Tank #2 close to 20, this was mainly the trip down to Eaglegrouch's which was a very hilly, curvy drive down, I took highway back, but haven't had to put gas in it yet, lol, so I'm thinking it's steadily on the rise from tank #1. Will report back on tank #3.

[shaggimo]

Oh yeah forgot to add, if the ignition module were going to overheat, I honestly think it would have done so on Sunday, I ran the car hard for a very long time and it was very hot out, normally I wouldn't put an old car through those motions, but I wanted set what the ole bird was made of, needless to say I'm impressed, temp even stayed at or under 200 all day  .

[ericarmstrong]

I love this mod! If my engine is ok I'm going to do this as soon as I find a bad  AMC printed IM. I like my GM tbi setup, but the less GM it looks the better.

[Jurjen]

This is a good alternative for the Motorcraft unit.
I like the way you build it in the old casing.
There are more links discribing this ignition, here is one:
http://www.carbdford.com/tech/HEI/hei.htm

[shaggimo]

Yup that's the same exact thing, I chose to use the factory case and harness just in case it does have a problem, I'll have no guess work on the side of the road, all I have to plug in the original unit and coil, and I'm back on the road, lol. And if any one ever looks, most will never know there's GM lurking in that ford box, haha.

Oh in that link, It's funny they show the WELLS module (what I used) as opposed to a factory GM.

[wagoneerhauler]

Ha.  I knew I had forgot to let you look for a heat sink.  I'll go through the box and see what I find that would fit in the original case.  The best thing to do would be to use the case as the heat sink but to do that and keep it stock looking would be the challenge.  One might be able to tig some studs inside for the HEI to mount to... ?

[simsx28]

where is the box located?

[ericarmstrong]

Ha.  I knew I had forgot to let you look for a heat sink.  I'll go through the box and see what I find that would fit in the original case.  The best thing to do would be to use the case as the heat sink but to do that and keep it stock looking would be the challenge.  One might be able to tig some studs inside for the HEI to mount to... ?

Why not jb weld? It holds studs in for valve covers so I'm sure it could handle the heat from an IM.

[shaggimo]

where is the box located?

Box is in the factory location, on the passenger side inner fender.

[shaggimo]

Ha.  I knew I had forgot to let you look for a heat sink.  I'll go through the box and see what I find that would fit in the original case.  The best thing to do would be to use the case as the heat sink but to do that and keep it stock looking would be the challenge.  One might be able to tig some studs inside for the HEI to mount to... ?

LOL, yeah I forgot all about that too. There is a couple things that stick up that you can bolt to (opposite of a stud, having brain lapse right can't think of its name, haha), that's what I bolted my current heat sink to, it seems to work ok. I used 1/4 plate steel, I really don't know how much heat it carries a way as opposed to aluminum though. The thing about welding or JB welding studs in would be you would need the module to be able to sit directly on the box, and not have an air gap, that would be the toughest part. The aluminum isn't that thick so drilling and tapping is out (unless you drill though, bolt and nut it). I'll see if my set up is sufficient in the long run, I may have to come up with a better method, I'm up to suggestions too. I have a couple other ideas too, but of course that would require special tools that everyone may not have access to(trying to keep it "poor mans hei"  ).

[Smitch]

Mount it in the snorkel of the air filter housing!   

[simsx28]

where is the box located?

Box is in the factory location, on the passenger side inner fender.

Thanks I feel stupid lol I am no mechanic and what is it for.

[shaggimo]

Basically it is the brain of the ignition system, I think I am explaining this correctly when I say, It takes a signal from the distributor, on when to tell the coil to throw a spark back to the distributor. I'm bad with explaining almost anything, haha, even if I do understand it  . Hope that helps a little.

[shaggimo]

Ok, so an update is due since I kept track of milage, first tank ran through the car: about 16 mpg, but keep in mind this car sat dormant for 15 years before I awoke it last year, also car had a weak pressure plate (clutch was slipping a bit). Tank #2 close to 20, this was mainly the trip down to Eaglegrouch's which was a very hilly, curvy drive down, I took highway back, but haven't had to put gas in it yet, lol, so I'm thinking it's steadily on the rise from tank #1. Will report back on tank #3.

So I dropped a bit on tank three, apx 18mpg. The car spent much more time on the highway at 70 mph though, I think that was a big killer of milage, still not too shabby though.

[blackeagle]

This is a great tip! Now, in what direction should the diode be mounted?
The link to junkyardgenius is dead.

[shaggimo]

Stripe toward the HEI module, try link again, worked for for me.

http://www.junkyardgenius.com/ignition/jeep/HEI01.html

[blackeagle]

Thanks! link wont work for me though.

[shaggimo]

Realizing I hadn't updated on this recently, I figured I'd give it a bump on the semi-long term. So far So Good! Even my temporary heat sink is doing its job, lol. I have had no problems what so ever with the upgrade, still running/starting good, still pulling 20+ mpg's. I may tinker with the timing a bit, it seems a bit on the slow side to me. Reguardless, I still would recomend this to anyone looking to eliminate the f*rd system on a tight budget.

*I checked, the instruction link is still good...

[shaggimo]

I haven't forgot about this, lol, I'm working on my revamped write up, with a proper diagram on how to do this so there will be no need to leave the site for advice, lol.

Oh, 9000 miles on the upgrade with no issues  (yeah we drove the heck out of it, lol).

[xtcinoz]

I found out that Auto Zone carries the Wells HEI module for $24.99 and it is Lifetime Guaranteed! If there isn't one near by you can order it on line autozone.com. I followed the junkyard genius directions and asked for a HEI mod for a 79 impala v-8.

[Canoe]

Heat sink.
If the plate you mount on can have more contact with the box, then the box and the inner fender it's bolted to become part of your heatsink capacity. The mounting plate could be slightly larger and then sandwiched between the stock box and it's bolt down points.

First wire-in of these I've seen that required a diode. Is this due to using the stock harness instead of the usual direct wire method?

As both the MSD coil and this Ignition Module can handle full voltage, does this wiring setup bypass the startup ballast resistor so your coil is running at full potential all of the time instead of only at startup?

Is this working with the stock ECM electronics setup or have you done the ECM By pass Test?



From notes gathered previously, Ignition Module for:
"'78 Camaro with a 350" or "1980 Camaro 3.8L"
AC Delco D1906
Wells DR100
Car Quest #21040
Napa: Echlin ECHTP45 or Mileage Plus #MPETP45SB
Niehof DR400
Standard LX301
(with a note to avoid Parts Master LX-301 - high failure rate reported)

[shaggimo]

Heat sink.
If the plate you mount on can have more contact with the box, then the box and the inner fender it's bolted to become part of your heatsink capacity. The mounting plate could be slightly larger and then sandwiched between the stock box and it's bolt down points.

First wire-in of these I've seen that required a diode. Is this due to using the stock harness instead of the usual direct wire method?

As both the MSD coil and this Ignition Module can handle full voltage, does this wiring setup bypass the startup ballast resistor so your coil is running at full potential all of the time instead of only at startup?

Is this working with the stock ECM electronics setup or have you done the ECM By pass Test?

On the diode, could be, I found a decent write up on it that stated to put it in there, so I followed their directions (I suppose it's there to prevent run-on, similar to what one has to do to put msd in a GM).

The start up resistor wire was controlled by the motorcraft ignition module, so yes coil and module get a full 12 volt zap.

The eagle I did this too, was an 81, so it had no ecm. In order to run this you would have had to do the nu-tt-er bypass.

[ammachine390]

In order to run this you would have had to do the nu-tt-er bypass.

Are you sure? The stock motorcraft ICM was made to be used the way you hooked up your HEI, but AMC made it work with the ECM. I would think that if you hooked up the appropriate wires from the wiring harness to the HEI module, it would still work with the ECM in the loop. The only difference would be that you would only have to hook up 3 wires to the HEI module for 83 and up models instead of 4 that you had to do for your 81.

However, you wouldn't be able to keep the ECM in loop (at least for timing control) for 82 models though as the MC ICM had a 3rd connector for the timing control, which an HEI module does not have.

[shaggimo]

Now you got me wondering if it would work with keeping the ecm in loop. Good point. I don't have vehicle to guinea pig that on, the 84 I have, has already been tampered with. Actually.......I may be doing some work on a bone stock 84 or 85 in the next few weeks, maybe I'll grab the module out of the sx/4 and see if it runs the other car with no issues, clear that up a little bit, lol.

[Canoe]

The start up resistor wire was controlled by the motorcraft ignition module, so yes coil and module get a full 12 volt zap.

How?
If you're using the stock wiring harness (it appears you are), then the coil gets full VDC when the ignition is starting, but is in series with the ballast resistor while running and does not get full VDC.
One of the main benefits of the GM-HEI IM with a TFI coil is you can bypass the ballast resistor to get full voltage to the coil all of the time. I don't see how swapping the stock IM for the GM-HEI IM using the stock connectors achieves this.

[shaggimo]

Well, I'll do a retest at home tonight with my volt meter with the ignition on "run" position, and see what I have. Im pretty sure I have a full zap to the coil in run position, I beleive I tested it back when I did this to the car because the same question arised, but that was over two years ago, lol, so we shall see....stay tuned 

[shaggimo]

As promised, I went out and checked the sx last night.


this is my volt meter hooked up to the battery, just to show it is accurate, and not giving false readings.


Here it is hooked to the positive terminal of the coil with the ignition in the run position. I did nothing to the cars' wiring, with the exception of spade terminals at the coil vs the oem horse shoe.

I didn't think of this til this morning, but I should have plugged the factory module back in and took a reading, oh well, maybe if it stops raining long enough I'll do that tonight for comparison sake.

[Canoe]

(Sorry I haven't got back for so long.)

If you (and prior owners) did nothing to the wiring, and did not remove or bypass the ballast resistor, then when the engine is running, the ballast resistor is in series with the coil (as shown in the wiring diagram).

This is why the write-ups that used to be around on this IM upgrade specify that to get the max from a TFI coil you can/should bypass/remove the ballast resistor.
(I have a vague recollection that bypassing the ballast resistor with the stock coil is not a good idea, no recollection why, but I'm not sure I trust my memory on that - it's late).

You can see the 0.2 VDC voltage drop between the two photos. But this doesn't mean much, because part of that voltage drop should be due to the load on the battery when you turn the ignition on.

With the ignition on, using the same ground point, you'd need to measure:
* the positive terminal of the battery, and then
* the positive voltage of the coil.
That at least will show you how much drop you're getting from the ballast resistor (and the wiring to the coil). But, this doesn't show what thpse values will be when running, as you should be seeing something in the order of 13.8 VDC supplied from the alternator (providing the accessories aren't pulling it down from too much current draw (I got the 94 amp one, nice)).

If you got that measurement, then that percentage drop should be around the same percentage drop of the maximum coil output.

Except, that's a static measurement, not a dynamic measurement.
There's something about the voltage reduction from the ballast resistor has more effect than expected. Something to do with the rise time of coil voltage becoming a factor as the rpm increases above idle, with a scope required to see the coil output degraded with the ballast resistor in series with the coil. I recall seeing scope photos that showed both a voltage decrease and a change in spark duration (decrease?).

In any event, bypass the ballast resistor and see how much improvement you get.
The jeep forums where this upgrade originated from claimed it was required to get the full bang from the TFI upgrade.
Those that bypassed the ballast resistor claimed they saw an improvement.
YRMV, but (prerequisite: this IM and a TFI coil) bypassing the ballast resistor is a really cheap upgrade.



p.s. found an article where they're putting this IM on Ford Probes, while keeping the ECM triggering it.
Instructions given are:
The ECU's trigger output wire (BL/O) feeds the HEI's pin 'G'.
Ground the HEI's pin 'W'.
Ground the HEI's base.
HEI's pin 'B' taps into the +12V dizzy feed wire (BK/P).
HEI's pin 'C' taps into the coil's primary wire (Y/G).

Claim is that their ECM is Negative Edge triggering, so no problem.
 
Also within the same collection of threads is a warning about failing Niehof DR400 version from Crappy Tire in Canada (but from five, six, years ago).