News: Putting FUN and FRIENDLINESS, FIRST into owning and learning about AMC small bodied cars, primarily Eagles, Spirits and Concords as well as vehicles built in AMC's Mexican subsidiary, VAM.

The AMC Eaglepedia can now be accessed using the buttons found below  This is a comprehensive ever growing archive of information, tips, diagrams, manuals, etc. for the AMC Eagle and other small bodied AMC cars. 

Also a button is now available for our Face Book Group page.


Welcome to the AMC Eagles Nest.  A new site under "old" management -- so welcome to your new home for everything related to AMC Eagles, Spirits and Concords along with opportunities to interact with other AMC'ers.  This site will soon be evolving to look different than it has and we will be incorporating new features we hope you will find useful, entertaining and expand your AMC horizons.

You can now promote your topics at your favorite social media site by clicking on the appropriate icon (top upper right of the page) while viewing the topic you wish to promote.


  • October 05, 2022, 11:04:37 AM

Login with username, password and session length

Author Topic: 82 ECM Test/ ecu bypass  (Read 463 times)

0 Members and 1 Guest are viewing this topic.

Offline Badger

  • Eagle
  • **
  • Posts: 10
  • Thumbs Up 1
82 ECM Test/ ecu bypass
« on: March 22, 2022, 07:02:41 PM »
Ok folks, After scouring all the information I could find, from this site and others, im still scratching my head as to what is going on. Im attempting to do the ECM Test/ecu bypass on my 82 eagle limited wagon, and to me, it seems as if it may have already been done? if so, very clean and profesionally.. I attached some photos, hopefully they work.
I think I understand the concept, and the way it should be wired to complete the bypass. My Orange and Violet wires are going directly from my distro to the Icm, not into the loom. Maybe there is something that I am missing or am misunderstanding. Iv heard the wiring on the 82s are different/interesting.
Thanks in advance!

Offline Badger

  • Eagle
  • **
  • Posts: 10
  • Thumbs Up 1
Re: 82 ECM Test/ ecu bypass
« Reply #1 on: March 23, 2022, 09:32:22 PM »
Anyone??

Online rmick

  • Eagle Sport
  • ****
  • Posts: 350
  • Thumbs Up 32
Re: 82 ECM Test/ ecu bypass
« Reply #2 on: March 23, 2022, 11:43:44 PM »
72 Javelin AMX
72 Javelin SST
72 Gremlin with 4.0
81 SX 4

Online rmick

  • Eagle Sport
  • ****
  • Posts: 350
  • Thumbs Up 32
72 Javelin AMX
72 Javelin SST
72 Gremlin with 4.0
81 SX 4

Offline Badger

  • Eagle
  • **
  • Posts: 10
  • Thumbs Up 1
Re: 82 ECM Test/ ecu bypass
« Reply #4 on: March 24, 2022, 12:58:20 PM »
Thanks, Iv seen that wiring diagram and many others on this site, jeep forums and the like, even the wiring diagrams in my Chiltons. Im just scratching my head looking at my wiring set up.. it doesnt match anything else iv come across.
Again its an '82 258 limited wagon.
The wires coming out of my Ignition Module are yellow, black/white, violet, orange, black/green, green. The violet, orange, black green, and green go into a plug, then violet, orange, black to directly to Distro. I cant find any evidence of there being cut wires elswhere or splices.

Offline MIPS

  • Eagle Sport
  • ****
  • Posts: 284
  • Thumbs Up 28
Re: 82 ECM Test/ ecu bypass
« Reply #5 on: March 24, 2022, 01:16:18 PM »
'82's with the three connector, yellow grommet ignition modules are special case and is different from all later models (in a good way). The distributor is wired directly to the module like a normal non-computer engine and doesn't pass through the computer, hence the wiring doesn't match the schematics you have. It looks professional because its factory. The computer control of the spark retard is the 2-pin connector with the yellow and black wires. TSM states to unplug and jumper these two pins to disable external spark control (locks the igniton at base timing so you can adjust it but I don't think there is anything wrong with just leaving it this way). I do believe at that point any standard blue grommet ignition module will work. You might need to double check this.

I scanned in the 82 model year schematics a while back while working on the computer. I'll try and attach them later.


Uh, if you are ultimately going to swap that module out and pull the computer I'd be more than willing to send a bit of money your way. ;)
« Last Edit: March 24, 2022, 02:14:43 PM by MIPS »

Offline Badger

  • Eagle
  • **
  • Posts: 10
  • Thumbs Up 1
Re: 82 ECM Test/ ecu bypass
« Reply #6 on: March 24, 2022, 02:24:11 PM »
Thank you so much, that is very helpful!
So by disabling the external spark control, would that also disable the stepper motor functions, as well as any other ECM funtions regarding vacuum delete? Id like to clean up my engine bay by removing as much of the vac lines as possible, thanks to the modified 258 vac diagrams I found here.
Again, thanks! I have been so confused about this for weeks!

Offline MIPS

  • Eagle Sport
  • ****
  • Posts: 284
  • Thumbs Up 28
Re: 82 ECM Test/ ecu bypass
« Reply #7 on: March 24, 2022, 03:02:18 PM »
No. the computer still continues to run even with the pins jumpered.
Follow the standard procedure for setting the stepper pins (or just switch carbs at that point) and then unplug the computer. That then disables the stepper motor, vacuum idle kick and upstream/divert solenoids and now the vacuum switch assembly and O2 sensor are no longer needed. The EGR, vacuum advance, CTO, TVS and air cleaner door flaps are their own vacuum routing and are not  part of the computer's wiring or vacuum routing. Keep the Sol-Vac around as it's also used by the air conditioning, headlights and rear defroster to increase the idle a little for the additional load.
If you only unplug the stepper motor and leave the computer running it will still attempt to run the idle kick and upstream/divert solenoids but no have spark or carburetor feedback, which might cause problems.
« Last Edit: March 24, 2022, 03:08:56 PM by MIPS »

Offline MIPS

  • Eagle Sport
  • ****
  • Posts: 284
  • Thumbs Up 28
Re: 82 ECM Test/ ecu bypass
« Reply #8 on: March 24, 2022, 07:52:32 PM »
Here's the ECM harness diagram for the 1982 model year.


Offline MIPS

  • Eagle Sport
  • ****
  • Posts: 284
  • Thumbs Up 28
Re: 82 ECM Test/ ecu bypass
« Reply #9 on: March 24, 2022, 08:03:27 PM »
Also here's the underhood wiring diagram for everything up to the firewall bulkhead.

Offline Badger

  • Eagle
  • **
  • Posts: 10
  • Thumbs Up 1
Re: 82 ECM Test/ ecu bypass
« Reply #10 on: March 24, 2022, 11:42:20 PM »
amazing! I plan on swapping to a Weber anyway, and then its as easy as unplugging the computer? Im also deleting my smog pump, cat, a/c, and anything else I can get away with, thankfully we have no emissions around here. ill make sure to keep the sol-vac for headlights and plug up any of the open vac lines from the deletes.
Again, thank you so much!

 

SMF spam blocked by CleanTalk