Page 3 of 3

Re: Adapting an EJ20G ECU

Posted: Thu Feb 10, 2011 10:09 pm
by rob
I updated the ignition part again.

-Rob

Re: Adapting an EJ20G ECU

Posted: Wed Jul 18, 2012 3:10 am
by DevC
Works great, thank you for the writeup!!

Re: Adapting an EJ20G ECU

Posted: Wed Jul 18, 2012 5:34 am
by rob
good to hear. Thanks for the feedback.

Re: Adapting an EJ20G ECU

Posted: Mon Jan 28, 2013 3:44 am
by logan9691
So with the pin47-6 purge control being removed from this ecu, do you think it's possible to remove the charcoal canister to help free up some room under the hood?

Re: Adapting an EJ20G ECU

Posted: Mon Jan 28, 2013 8:04 am
by mike-tracy
It is possible. I run a 2-port N/A canister instead. It could be my imagination, but the car seems to run better with it connected.

Re: Adapting an EJ20G ECU

Posted: Mon Jan 28, 2013 3:56 pm
by Legacy777
Yeah, I'm running a 2-port non-turbo canister and haven't had any issues.

Re: Adapting an EJ20G ECU

Posted: Mon Jan 28, 2013 7:24 pm
by logan9691
No, I'm talking about taking the canister out completely. Whether its 2 port NA or 3 port turbo the damn thing takes up equal amount of room. If the purge solenoid isn't being used, what's the point of having it?

Re: Adapting an EJ20G ECU

Posted: Mon Jan 28, 2013 8:27 pm
by wtdash
Josh replied to your otherpost:
Legacy777 wrote:You can remove it, but pressure will build up in the gas tank. The normal hiss you hear when opening the cap will become a hisssssssssssssss. I'm serious. I didn't run the canister for a while and at fill ups it hissed for a ridiculously long time.

Does the 20g ECU have any canister purge control pin? If so, I'd just repin that pin.

Re: Adapting an EJ20G ECU

Posted: Tue Jun 30, 2015 9:26 am
by Dynamic Entry
Legacy777 wrote:The MT harnesses should not have a wire there. If they do, I'm not sure where it would go. It should not be grounded though.

It's an input to the ECU. Grounding that pin tells the ECU whether the trans in the car is MT or AT. The ECU will alter idle speeds/loads and timing to properly adjust idle. There may by some additional minor stuff that the ECU changes, but I don't really have any info on that.

Subaru apparently put both sets of info/code into the ECU. When I did my AWD & 5spd swap, I was using my 90 AT ECU hooked up to a MT. All I had to do was snip that MT/AT identifier pin. Everything worked great.

One thing to note. The later first gen non-turbo legacies 92+ apparently had reversed AT/MT identifier pins. They were reversed from what the 90-91 MY's had, and were incorrect when compared to the factory manual. However, that issue does not affect the turbo ECU's, all years 91-94. I bring this up in the event someone is swapping in a turbo motor into a 92+ non-turbo legacy and keeps the existing harness.
rob wrote:Thanks for the insight Josh. I removed the AT/MT pin concern from the list.
I have a 93 SS that was an automatic and has been swapped to manual. What does this mean regarding the MT/AT pn in this specific case.

Re: Adapting an EJ20G ECU

Posted: Wed Jul 01, 2015 5:39 am
by wtdash
Dynamic Entry wrote: I have a 93 SS that was an automatic and has been swapped to manual. What does this mean regarding the MT/AT pn in this specific case.
Should not be an issue.

Are there any issues w/your car related to the trans swap? If the car ran fine on the stock ECU after the swap, the EJ20G shouldn't matter, as long as the EJ20G-specific wiring is addressed.
TD

Re: Adapting an EJ20G ECU

Posted: Sun Jul 05, 2015 3:42 am
by Dynamic Entry
wtdash wrote: Are there any issues w/your car related to the trans swap? If the car ran fine on the stock ECU after the swap, the EJ20G shouldn't matter, as long as the EJ20G-specific wiring is addressed.
TD
No, the trans swap is complete with no issues.

The thing is that I never really ran it on the stock ECU, it was always piggybacked or otherwise.

The reason I asked is because it seemed like a unique combination of variables that I have that most others don't. Everything is running great, I just didn't want to miss anything.

Thanks!

Re: Adapting an EJ20G ECU

Posted: Sun Jul 05, 2015 4:07 am
by wtdash
FWIW, many have done the swap and then upgraded to the Rob Tune/RT...I got there by doing the RT b4 the 5-speed swap, but no issues.

Have fun!

Re: Adapting an EJ20G ECU

Posted: Wed Jan 18, 2017 9:32 pm
by pabst90-ix
Ok well this is a serious amateur question, could someone please explain what is meant by merging the pins for the ecu? Cut solder? Seperate from pins then join together. Im slightly confused as i have never done anything like this.

Re: Adapting an EJ20G ECU

Posted: Thu Jan 19, 2017 6:02 am
by wtdash
Use a Scotch-lock or similar connector ( I like the T-taps).

DE-PIN the B48-5 from the ECU harness plug and connect the wire to the B48-21 w/the T-tap, Scotch-lok, etc.

B48-21 needs to stay connected 'as is' so the ECU can use it.

That help?

Google any 'how tos' if want to see it.

This SVX video is almost identical to the '90-'94 Legacy ECU connectors for a How To on De-Pin: https://www.youtube.com/watch?v=ayxEfRvhLEE

GL,
TD

Re: Adapting an EJ20G ECU

Posted: Thu Jan 19, 2017 2:41 pm
by pabst90-ix
Thats perfext, thanks. I just wanted to make sure i was reading the instructions right. Everything is in place just had to double cbeck.

Re: Adapting an EJ20G ECU

Posted: Sun Jun 18, 2017 12:08 am
by Huelsdonm
I just got my ej20g ecu and I have two ignitors to wire in, this is a great write up and thanks for the help. I do have a question though; why can't I just merge the trigger pins from the ecu before the ignitor instead of wiring in two ignitors and merging the coil triggers? Does it hurt the ecu to back feed the signal? Will it mess with timing control or dwell? I read this article http://www.rs25.com/forums/f106/t64017- ... h-etc.html (sorry for linking to another site if it is forbidden) and this is exactly what supermoose did. It seems like a very simple solution but I'm sure there are good reasons not to do it this way or it would have been recommended already over here. Maybe I could put a couple diodes in there to avoid ecu damage? If that is the worry? I know rob has spent a lot of time doing developing his methods and I completely trust them, I'm just lazy and looking for shortcuts, hahaha.

Thanks,
Alex

Re: Adapting an EJ20G ECU

Posted: Mon Jun 26, 2017 5:39 pm
by Legacy777
Welcome to the BBS.

I would think if you keep from back feeding signal to the ECU I would think you'd be ok, but it'd probably be good to get some additional feedback. Worst case, you give it a try and let us know. :)