ECM Test Bypass Help

[Prafeston]

1983 AMC Eagle Limited

I'm trying to follow directions given by GRONK and also some charts and directions found online here:
http://www.amceaglesden.com/~iowaeagl/guide/index.php?title=Diagnostic_ECM_Test




It looks like I'm supposed to be taking the Orange and Purple Wires from the Distributor and Splicing them straight into the Ignition Module(IM). I don't see a problem with the purple one as I see from the diagram the purple wire leaves the IM, but it only goes to the plug and then disappears so you just splice it in right there in that area between the IM and the plug.



The diagram shows the that you splice in at the firewall, but the orange wire that leaves the IM also disappears at the plug like the purple one does. So can I splice both of the wires in before the plug? The three wires leaving the plug are black, green, and light green. Like it shows in the diagram for the '86 model.

'86 Diagram



So how do I need to go about this? Seems like the most logical thing would be to splice the orange wire in before the plug just like you do with the purple one.

Also in GRONK's instructions you are also supposed to splice into the the Ignition Coil(IC) before and after the resister in the red wire. Well, the wire that came with GRONK's kit is red, but the wire I had to splice into is yellow. That wire goes into what looks like a resistor and another yellow wire goes comes out and goes to a ground. So GRONK's kit has a red wire and a green wire(actually two green wires) and the stock IC had a yellow and a green wire. Did I hook this up right going green to green and red to yellow?





GRONK's diagram also shows that you'll be splicing in the red wire from the Starter Solenoid(SS) into that red wire leaving the IC, but my SS has a red wire with green stripe and yellow wire leaving the same connection with the green wire on the other connection. So I'm not really sure which wire should be spliced.



Then again on GRONK's diagram I'm supposed to splice the red wire from the IM into the red wire leaving the resistor from the IC (which in my case is yellow), but the red and white wires leaving the IM go to a plug and then turn into yellow and green wires. In general I'm just quite confused about what I'm supposed to be doing since none the the wires seem to be the same color as what's in the diagrams.

[ammachine390]

I assume you are also dong the TFI/MIU upgrade, using a pertronix ignition coil. I'm a little confused about what you spliced into your ignition coil. When I did the MIU upgrade, I cut the yellow wire on the starter solenoid, and then spliced it into the yellow wire on the harness side of the 2 wire plug for the ignition module. That will bypass the ignition resistor (unrelated to the computer bypass).

http://www.amceaglenest.com/images/Eaglebook/MIU.pdf

[Prafeston]

I assume you are also dong the TFI/MIU upgrade, using a pertronix ignition coil. I'm a little confused about what you spliced into your ignition coil. When I did the MIU upgrade, I cut the yellow wire on the starter solenoid, and then spliced it into the yellow wire on the harness side of the 2 wire plug for the ignition module. That will bypass the ignition resistor (unrelated to the computer bypass).

http://www.amceaglenest.com/images/Eaglebook/MIU.pdf

I did the TFI(Ignition Coil) upgrade from GRONK. His kit comes with a plug that plugs into the new coil. That plug had 2 green wires and one red wire.

[Prafeston]

Thanks for the link Regal!

[Prafeston]

Ok, I still need some help here.

I did this bypass orange/orange and purple/purple and now the car will start, but will only run when I've got the key still pushed forward in the start position. As soon as I put it in On after starting it cuts off...but then when I turn the key to Off it acts like it was still kind of running and I can hear it power down.

What have I done wrong? There is still the IC and SS splicing that it seems like I need to do juding by the pdf of GRONK's. I've tried calling and texting GRONK, but I'm getting no response and his voicemail box is full. He is a busy man!

Need some help! AHHh

[IowaEagle]

Jurgen is an expert on this too.

[eaglefreek]

Ok, I still need some help here.

I did this bypass orange/orange and purple/purple and now the car will start, but will only run when I've got the key still pushed forward in the start position. As soon as I put it in On after starting it cuts off...but then when I turn the key to Off it acts like it was still kind of running and I can hear it power down.

What have I done wrong? There is still the IC and SS splicing that it seems like I need to do juding by the pdf of GRONK's. I've tried calling and texting GRONK, but I'm getting no response and his voicemail box is full. He is a busy man!

Need some help! AHHh

Sounds like your only getting power to the coil when it is in the start position only. With a volt meter, check the + side of the coil with the key in the run position and see if it has power.

[Prafeston]

I hate electrical work. I have a volt meter, but I have no idea how to use it. It has a switch on to turn it on with like a million different ranges and DC/AC and what not. I have no idea what position it needs to be in. And where do I put the red and black prods to check the voltage?

[Prafeston]

Well I decided I'd just try to do the splicing with the IC and SS that is in the diagram of GRONK's but the red wire coming from the SS that I'm supposed to splice into the red wire coming out of the IC specifically says "Resistance Wire - Do Not Cut or Splice"

...there was the Yellow wire coming from this same connector on the SS...should I splice that in instead?

[eaglefreek]

It sounds like you have it hooked up right. Regarding the yellow wire in this pic, where you can see the yellow wires make a Y, that should be 12v when in the START position. The other end of the resistor, the black thing, should be 12v when in the run position but will be less after running through the resistor. Probably closer to 8v. It shouldn't be going to ground.

In your voltmeter, set it to 20 on the DC side. Red to the positive side of the coil, the red wire and black to the negative terminal of the battery or any bare metal part on the car.



So when measuring at the + side of the coil you should have at least 12v when in the start position and less than 12v when in the run position, probably 6-8v. You'll need a helper to turn the key for you.

[Prafeston]

I've got no helpers tonight. I'll try tomorrow. Thanks for the explanation. Yeah, the black resister has the yellow wire going in, then the yellow wire come back out that same end....the other end of the resister has a black wire going to ground.

I also just spliced into the yellow wire coming out of the resister with the yellow wire coming from the IM, though from GRONK's picture it's supposed to be a red wire, but when it comes out of the #2 plug it turns into a yellow wire and I figured logically yellow to yellow sounds good.



After I did that it's still doing the same thing, I'm waiting to see what I should do about that red wire coming from the SS that says not to cut or splice.

[ammachine390]

Regarding the yellow wire in this pic, where you can see the yellow wires make a Y, that should be 12v when in the START position. The other end of the resistor, the black thing, should be 12v when in the run position but will be less after running through the resistor.

The black thing on the yellow wire is not a resistor. That is the plug for the radio interference capacitor to plug into. The ignition resistor looks like a regular wire.

[GRONK]

Not sure if I caught this in time.

The n u t t e r bypass is actually VERY simple.

If you attempt the bypass and you won't start not, SOMETHING is wrong.

Here it is in a nut shell:

Start at the ICM.  Leaving the ICM, tap into the violet wire, prior to the 1st connector.  Add a splice there (16 gauge) and run a section of wire to the violet in on the distributor.  Use a barrel connector and disregard everything else.

Note:  make sure the splice after the ICM is a 3 way splice.

Now, at the ICM, AFTER the 1st connector, you will either have an orange wire, OR a light green wire with a black tracer.  Cut this AFTER the 1st connector, add a barrel connector and run a 16 gauge wire to the ORANGE wire going into the distributor.  Disregard everything else.

THAT IS IT.

If you are not running, you made a mistake somewhere.

Notice that I said at the ICM, after the 1st connector the wire might be orange and it might be light green with a tracer.  6 and 1/2 dozen on this one.  No need to trace anything through the loom or into the firewall.

On wiring the coil, the new coil, no matter which style it is, will have a + and a - input.  connect the new coil EXACTLY as your old one is connected.

[eaglefreek]

Regarding the yellow wire in this pic, where you can see the yellow wires make a Y, that should be 12v when in the START position. The other end of the resistor, the black thing, should be 12v when in the run position but will be less after running through the resistor.

The black thing on the yellow wire is not a resistor. That is the plug for the radio interference capacitor to plug into. The ignition resistor looks like a regular wire.

You are correct. I got rid of mine a few years ago when I installed a MSD and was trying to go by memory. 

[Prafeston]

Thanks GRONK, looks like I need to redo my connection at the ICM. I spliced the orange straight into the orange before the first plug and from what you are saying I apparently need to splice the orange into the light green after the first plug.

It also sounds like maybe I don't need to do any splicing into the Ignition Coil after just installing the new connector you gave me and plugging it in.

[carnuck]

Here's the link to my old page (IIRC by Terry Howe)

http://www.oocities.org/eaglemania2002/bypass.html

[Prafeston]

Well I made a little video last night of how it's wired up. Figure it might help someone else some day.

http://www.youtube.com/watch?v=MDii9tOKHC4

If I did something wrong let me know!

Also I thought it was doing pretty good yesterday, but now it's back to the same old thing it was doing before. It's taking like 10 seconds or so with the key in the start position before it finally starts up. Also yesterday it was idling fine...almost too low and now today it's back to idling really high and when I put it in park it starts revving up. I still need to do the timing I believe. Gonna purchase one online. Autozone has one for 40 and a digital one for like 99, but I'd rather pay like 15-20 for one online.

[68AMXGOPAC]

I've had the cheap ones, but last year bought a nice digital one that also reads rpm on the screen directly.It can also be used on 6V systems , wich was a big plus when Dialing in an old 52 Molines I was setting up , and a 50 GMC I have in the shop.
If you only use it occasionally, then what your looking at will probably be good enough.Good Luck Master Chief.

[eagle503]

I found this to be helpfull
http://home.sprynet.com/~dale02/ignmods.htm
And correct me if I am wrong but I dont think it matters what side of the plug you put the orange wire on.
So if this mod removes the MCU from the loop will this effect sport models with tachometer?

[Prafeston]

And correct me if I am wrong but I dont think it matters what side of the plug you put the orange wire on.

When I had the orange going to the orange before the plug the car would not start. Once I moved it to the Light green wire on the other side of the plug it started right up.

[ammachine390]

So if this mod removes the MCU from the loop will this effect sport models with tachometer?

Nope, tach is wired directly to negative side of ignition coil, no ECM input at all.

[rollguy]

I would like to do this one day with not cutting any wires.  My plan is to go to the wrecking yard and get some plugs and connectors off of an Eagle, and make a harness that just plugs in.   I am in CA, and an emissions test is done every other year.   I need to have everything made reversible for when test time comes.  Maybe a kit could be made that just plugs in and does the bypass without cutting any of the stock wiring?    How about it all you automotive electrical engineers? What do you think?

[Prafeston]

I would like to do this one day with not cutting any wires.  My plan is to go to the wrecking yard and get some plugs and connectors off of an Eagle, and make a harness that just plugs in.

That sure would be nice!

[eagle503]

And correct me if I am wrong but I dont think it matters what side of the plug you put the orange wire on.

When I had the orange going to the orange before the plug the car would not start. Once I moved it to the Light green wire on the other side of the plug it started right up.

when you had it on the "wrong side" was it connected to both the plug and icm or just the icm ?
The purple wire is connected "T" style . Did you have the orange hooked up the same? that could have been the problem. The Light green wire needs to be removed from the circuit correct? If you simply tap into it "T" style the distributor would be getting two different spark signals.

[mudkicker715]

I would like to do this one day with not cutting any wires.  My plan is to go to the wrecking yard and get some plugs and connectors off of an Eagle, and make a harness that just plugs in.   I am in CA, and an emissions test is done every other year.   I need to have everything made reversible for when test time comes.  Maybe a kit could be made that just plugs in and does the bypass without cutting any of the stock wiring?    How about it all you automotive electrical engineers? What do you think?

or simply get solderless connectors and make your own harness. i did when it mattered for some reason

[Prafeston]

when you had it on the "wrong side" was it connected to both the plug and icm or just the icm ?
The purple wire is connected "T" style . Did you have the orange hooked up the same? that could have been the problem. The Light green wire needs to be removed from the circuit correct? If you simply tap into it "T" style the distributor would be getting two different spark signals.

I think I understand what you mean, and I did T connect them so that could have been my problem. I guess I should have just connected straight into the orange wire going into ICM, this could have solved my problem.

[eagle503]

when you had it on the "wrong side" was it connected to both the plug and icm or just the icm ?
The purple wire is connected "T" style . Did you have the orange hooked up the same? that could have been the problem. The Light green wire needs to be removed from the circuit correct? If you simply tap into it "T" style the distributor would be getting two different spark signals.

I think I understand what you mean, and I did T connect them so that could have been my problem. I guess I should have just connected straight into the orange wire going into ICM, this could have solved my problem.

The reason I was curios is that I bypassed the plug with both wires and had no problem. There is not much you can do to mess this up and really the only thing i can think of is leaving the light green hooked up to the mcu.

[Prafeston]

Well it makes sense what you are saying. I guess had I just done orange to orange before the plug and not done a 3 way T connection and just gone orange from distributor to orange going into the ICM then it should have worked. Oh well. The only reason I see for doing it on the other side of the plug is you have more wire to work with when you are having to do your splicing. The limited amount of wire and space between the ICM and the plug made it kind of hard to splice in there.

[carnuck]

For the non-cutting way of doing this, find an '80/'81 and get the whole underhood harness from a non-electronic BBD model. I wonder if the CARB certified TBI Holley projection would work on the Eagles as well as it did on the CJs?

On the hard starting:
In this pic the 2 small wires on the solenoid are marked "I" for ignition and "S" for start. Hook a voltmeter to the "I" terminal. With the key on, voltage will be the same as at the coil (about 9VDC) When you turn the key to start, the voltage should pop up to 12VDC or whatever the battery voltage is during cranking. If it doesn't, the voltage will drop, which makes the coil's voltage spike drop and plugs don't get enough secondary winding voltage right away to clear off and run.


If the power doesn't spike up, the contact inside the solenoid is worn off.

[rollguy]

I would like to do this one day with not cutting any wires.  My plan is to go to the wrecking yard and get some plugs and connectors off of an Eagle, and make a harness that just plugs in.   I am in CA, and an emissions test is done every other year.   I need to have everything made reversible for when test time comes.  Maybe a kit could be made that just plugs in and does the bypass without cutting any of the stock wiring?    How about it all you automotive electrical engineers? What do you think?

I figured it out, and it was EASY!
I started a new topic:
http://forums.amceaglenest.com/index.php?topic=38916.0

[carnuck]

Another partial option is when the motor is cold, turn the key to on, and unplug the stepper connector on the back of the carb. I did that on my '83 Cherokee.

[Asphalt]

Hello     , I just did the bypass & yes its fairly EZ   .     I did look at the short video Prafeston posted on u-tube( thankz), & she started immediately. Advanced the timing & my '86 Eagle is running great.