22R Ignition Control Module and Ignition Coil GM Swap. Wishful thinking or possible?
 

This is a conversion I had recently learned about while searching the forums after my stock 30 year old ignition control module died. I performed the conversion exactly as described in a number of the write ups that are floating around the forums. Below is a picture of what my ignition system now looks like. It works pretty well... for a little while. The truck randomly dies and loses all spark from time to time. Sometimes it will go a few days without dying and other times it will lose spark and die several times in a row. If I quickly flip my ignition off and back on while rolling along I can keep right on driving without even stopping. The interesting part of my problem is that if I simply turn the key forward to restart the engine it will crank and crank and crank and not start. I HAVE to turn the key backwards into the off position first and then forward again and it fires up every time. I don't know why this is so. I don't know what the act of turning the key into the off position is doing. Something about turning the key backwards is resetting something and allowing current to flow again or something. I don't understand it and don't know what to do to fix it. I'll also note that the distributor and the distributor cap + rotor on my truck are also brand new. I have the ignition module mounted on 2 heat sinks and it is November in Maine right now - so I doubt it's a heat issue.

When you browse through the various threads on doing this GM ignition swap you see page after page after page of people asking questions and people having difficulty with what has been described in a few videos and writes ups as being a very simple and effective conversion. What I don't see much of in these threads are folks who have completely successful and 100% reliable results showing the clear path to accomplishing the mod. My question is - Has anyone here successfully done this conversion and had it operate consistently and reliably? What are so many people missing that is causing them trouble in what seemed to be a simple conversion?

https://cimg9.ibsrv.net/gimg/www.yot...b03bb26e03.jpg

Do you know if your truck has an IGF lead from the ignitor? It may be limited to fuel injected; I don't know.

If the ECU doesn't get the IGF signal (for 4 consecutive ignitions, according to the manual), it shuts off the injectors to avoid shooting unburned fuel into the Catalytic Converter. Then the truck stops. When you turn the key to off, the ECU resets and starts the count over.

On a modern truck the lack of IGF throws code 14; on older 22re s it should throw code 3

A schematic of just how you have this wired into your truck harness would be a big help

also just what year is this indeed a 1986??

I don't know anything about an IGF lead so I can't say for sure at the moment. That sounds like a pretty rational theory you have though. Have you done this GM conversion? I'm really hoping to hear from people who have done it and who say it works great and has been reliable for years. I don't mean to be cynical but I have doubts as to whether or not anyone has actually gotten this to work properly. I just haven't seen it yet. I really hope I'm told I'm wrong and that it can be done. I'm concerned that the couple videos I've seen and write ups I've come across explaining how to do it were made by folks who were excited when they first got it all hooked up and it seemed to run and drive great. Mine ran great too, at first. It wasn't until I'd been driving it for a few days that problems began to arise. It still runs great 90% or more of the time. But it fails on me enough that it's definitely a problem.

Yup it's a 1986. Good guess! 22R with carburetor. I'll see if I can find a good way to illustrate exactly what's going on with the wires in that photo. Some of it you can pretty clearly see in the photo. White and pink wires go to the distributor and I believe it's all grounded pretty well.

Also, for anyone who may be unfamiliar with the GM Ignition Conversion, it is essentially simply replacing the stock Toyota Ignition Control module with a GM unit. Really the only reason to do this is because a new Toyota unit cost at least $250 + and a GM unit can be found for as low as $20. So the idea was that instead of buying an incredibly expensive aftermarket or OEM Toyota unit you could buy cheap GM units and even keep a few in the glove box as spares.

Some people have said that you can use the stock Toyota Ignition Coil with the GM Ignition Control Module if you incorporate a small 1/4 watt 1K ohm resistor. I have no idea why some people have recommended using the resistor with the stock coil. The answer may be somewhere in the threads linked below or maybe someone on this forum knows. I haven't read every bit of the threads I've linked below but I have read quite a lot and I could only find people saying to use it but not why. The other option was to use a different ignition coil. The one that I had seen most recommended was the Accel 140008 Supercoil as pictured in the photo I posted at the beginning of this thread.

Here are relevant links about the modification:

https://www.yotatech.com/forums/f116...ersion-211966/
http://www.pirate4x4.com/forum/toyot...coil-30-a.html
http://bbs.zuwharrie.com/content?topic=85514.0
https://forum.ih8mud.com/threads/ign...skates.802849/
https://www.davezoffroadperformance.com/forum/viewtopic.php?f=4&t=1319
http://4x4wire.com/forums/ubbthreads...te_id/1#import
http://board.marlincrawler.com/index.php?topic=75381.0

Well, for what it's worth, RockAuto has an aftermarket ignition control module (igniter) for $86. My favorite online Toyota dealer http://parts.lakelandtoyota.com/ has a drawing of one, but no part number (so no price).

So using a $20 (really?) GM control module could save you about $66. So considering the time you've put into this (you're citing to a lot of non-YotaTech sites; coming here makes you sound a little desperate), you're paying yourself, what, $0.14/hour so far?

And to answer your question, no, I haven't done this conversion. I don't know much about the ignition on an '86. And reading through a few of the sites you cited to, I'm not to sure the posters there did either.

All the sites I linked to are simply the whole first page of results from google if you type in 22r gm ignition conversion. I added all the links real quick just so all the info would be gathered in one spot. I've spent a few hours reading through them and a few hours installing the new parts. That $86 ignition module on rockauto is not the correct one I don't think... That's for a 22re I believe? I hope I'm wrong. If I found one for $86 I'd buy it. But it looks nothing like the one for the 22R. The least expensive unit that appears correct on Rockauto is $280.99. Here is the exact GM module that I have in my truck right now: https://www.amazon.com/Standard-Moto.../dp/B004BTQAKA

I've done the conversion on my 87 22r and have no troubles whatsoever. The only thing that will shut down spark is the loss of the key on positive signal to the coil or the pickup in the distributor not sending a signal to the igniter. But in your case it sounds like the positive wire needs some troubleshooting. Where does that wire get the signal?

Excellent. Glad to hear it. How long have you had the conversion done?

My wiring uses all of the existing wires that originally went to the stock ICM. I haven't drawn from any other sources. As you can see from my photo, I have two wires on both the B and C connectors on the module. The two wires on B are 1: the power source that originally went to the stock ICM and 2: the positive connector on the ignition coil. The two wires on the C connector are 1: the ground that went to the original ICM and 2: the negative connector on the ignition coil. I think I'm describing that correctly.

What ignition coil are you using with your setup? And what brand ICM? Do you have two wires on your B and C connectors like I do or is yours different?

Myself I would have found a used igniter or bought a new one

If GM parts are like every thing else made in China I wonder if your module is bad

I've tried a couple different of the GM ignitors.

If I knew I was going to have trouble with the conversion I would have found a used one too. Even used ones can go for a good amount of money though. At certain times in my life I've had a lot of money. At others times not so much. This is one of those not so much times. If I felt perfectly fine spending nearly $300 on a brand new aftermarket ignitor I would have done it. An actual brand new Toyota OEM ignitor is even more expensive.

It's not like this conversion took days of work though. It just involves cutting some wires, fitting new connectors, drilling a few holes and mounting the new ignitor and coil. It would be pretty easy to revert back to the toyota parts.

I may not be correct because it has been a while since I did it but I believe I walked into the auto parts and told them I needed all parts for a 1975 Chevrolet half ton pickup and I just picked a coil off the rack that did not require an external resistor. All the wiring that I saw in your picture appears correct that's why I was questioning the key on source.

Alright, I think I might have a solution to your problem. The wiring here is a bit jumbled but from what I can see the Ground is connected improperly. Again from what I can see, There is a black wire going to the ground terminal of the module to the Controle side of the module for the coil. Doing this will essentially bypass or in your case reduce the effectiveness of the control side of the Module. My guess is you got lucky and the module has just enough ground from the mounting plate to allow it to run but with just enough resistance to allow the control side of the ignitor to induce mutual induction in the coil.

Little Electrical 101 side note.
Ignition coils have two coils a primary and a secondary. The primary side gets energized and magnetized by the 12v ignition power and is controlled by a ground side switch (module).

When the Module sees its time to create mutual induction it opens the ground side of the primary coil to allow the magnetic field to collapse the Secondary coil then absorbs the collapsing magnetic field and multiplies the voltage during this microsecond process to create thousands of volts to send through your wires and plugs.

with the Coil wired straight to ground the Primary wouldn't see mutual induction or in your case would see minimal mutual induction.

My recommendation would be, Cut the ground wire going from the module's ground to the Controle side of the module and move it to a better ground on raw metal thars not painted, coated, or corroded.

This thread was nearly three years old man. haha

But since I noticed your reply I may as well update. Three years later I'm still rocking the GM ignition control module conversion in the same truck. My problem seems to have been the particular brand of module. I tried a couple different brands and the results were inconsistent. I would periodically lose spark completely. Finally I tried a Delphi DS10071 Ignition Control Module (which looks identical to the others I had tried) and this one worked and has worked everyday for the past three years. It's been completely reliable. I keep a couple spares on hand.

Going through the same problem. Got a standard motor products control unit. Getting spark intermittently. Very frustrating.

im considering getting the Delphi to try.

the171, I'm not sure what module you're talking about but if you're doing the GM HEI swap, then you should check the reluctor gap in your distributor, which controls the strength (in milivolts) of the signal it sends to the module. The GM ignition module is designed to work on a signal that is about 10x the voltage of the Toyota unit but it is also pretty flexible. I found on my own swap that I had to reduce the reluctor gap to just a hair under the lowest recommended clearance to get a signal strong enough to trigger the GM module.

With the stock clearance, the GM ignition wouldn't fire at all. I'd crank and crank and nothing. Reduced the clearance just a tiny bit and it fired right up on the first try. Amazing what a few thousandths of an inch can do.