EJ18 ECM

[djellum]

Hello,

getting prepped for a swap.  I have an EJ18 complete with harness but no ECM.  Was bought on a pallet so I don't know what vehicle it was out of.  Are their any differences in the ECM from year to year or will any EJ18 one work.  if there is a difference are their any markings on the engine itself that would tell me what generation of 18 it is?

[idosubaru]

I bolt an EJ22 manifold to the EJ18 then use an EJ22 ECU.

Much easier and then you have more parts and knowledge base availability.

As to your EJ18 question....From the little I’ve seen (which is not a lot of EJ18 world), I think they’re all interchangeable. 90-96 Imprezas. 
 

Edited October 6, 2020 by idosubaru

[idosubaru]

I probably tossed it to scrap but I used to have an EJ18 ECU 

[djellum]

if you find it message me and ill throw some cash at you.  if I have to i will get a whole system, but seems a waste when I only have to get a control unit.

[wtdash]

The 1.8 isn't my forte, but I'd 'think' (!) that the ECU / ECM changed with the OBD2 implementation in  '95-'96, since it did on the Legacy.

Per Ebay....they did: Find the ECM harness plugs and match to the below links...the harness plugs will match the color of the ECM's.

 

 

1993-1995: https://i.ebayimg.com/images/g/aE4AAOSwgQ9ViZQn/s-l1600.jpg

1996+: https://i.ebayimg.com/images/g/UesAAOSwcJtc2yb4/s-l1600.jpg

 

 

 

 

 

 

Edited October 8, 2020 by wtdash

[djellum]

Awesome, thanks a bunch

[el_freddo]

EJ22 engine management is the go. It’ll give you the option of upgrading the block later down the track. 

You will probably have to fit a cam angle sensor as I don’t think the EJ18 uses one - another reason to avoid this setup. 

Cheers 

Bennie

[djellum]

is it really upgrading though?  I dont really want a ton of power, just non discontinued parts and the best gas mileage i can get.  I can get a control unit and have the complete setup, if it came to using another one I would just get the 2.2 complete.

is the 2.2 that much better?  

[idosubaru]

honestly the older Imprezas are known for being capable of good gas mileage and have basically no known issues and will meet your needs just fine.  the ones I’ve swapped didn’t have a knock sensors.

I’m suspect of that 1996+ EJ18.  Is there a part number to cross reference?  the EJ18 was, for practical purposes, almost unavailable in 1996 and definitely not later as that listing suggests. That was it’s last year and a unicorn at that. There’s a strong chance that theres bleed over or hold over or prior year shuffling and all EJ18s are the same, old style.  Maybe new exists but is definitely confirm before relying on an eBay picture.

Id lean towards an EJ22 just because the intake isn’t a convoluted mess of hoses and contraptions, can be found without EGR, and easier to find parts.

if this is for an automatic you’ll have the CEL on if you run it without EGR. but it runs fine like that. EJ22 intakes are cleaner and have knock sensor capability as well.

 

 

[idosubaru]

On 10/6/2020 at 9:31 PM, djellum said:

if you find it message me and ill throw some cash at you.  if I have to i will get a whole system, but seems a waste when I only have to get a control unit.

I can’t find it. I couldn’t find any EJ ECUs and doubt I would have thrown them all away. But anyway I don’t have one I can send now. They won’t be hard to find, there’s zero demand. 

Edited October 9, 2020 by idosubaru

[wtdash]

13 minutes ago, idosubaru said:

honestly the older Imprezas are known for being capable of good gas mileage and have basically no known issues and will meet your needs just fine.  the ones I’ve swapped didn’t have a knock sensors.

I’m suspect of that 1996+ EJ18.  Is there a part number to cross reference?  the EJ18 was, for practical purposes, almost unavailable in 1996 and definitely not later as that listing suggests. That was it’s last year and a unicorn at that. There’s a strong chance that theres bleed over or hold over or prior year shuffling and all EJ18s are the same, old style.  Maybe new exists but is definitely confirm before relying on an eBay picture.

Id lean towards an EJ22 just because the intake isn’t a convoluted mess of hoses and contraptions, can be found without EGR, and easier to find parts.

if this is for an automatic you’ll have the CEL on if you run it without EGR. but it runs fine like that. EJ22 intakes are cleaner and have knock sensor capability as well.

 

 

 

Tangent: Please see http://www.cars101.com/impreza_archive97_98.html

'97 was the last year of the 1.8, per cars101.com. And the ebay pics are legit based on the part number 22611AC450.

 

Back to topic:  Yes, the EJ22 IM + ECU is good.

[idosubaru]

Got it. I clicked on the eBay pics but they were onky pics and not the listing. And I don’t have connectivity that favors searching.

Then the 96+ EJ18 ECU might be interchangeable with EJ22 ECUs since EJ22 and EJ25 of the same era are plug and play swappable. Auto/manual doesn’t even matter. If that’s the case he could use any EJ22 or even EJ25 ECU from a phase I 96-99, if his current set up is the later OBII variety. 

[idosubaru]

On 10/6/2020 at 9:31 PM, djellum said:

if you find it message me and ill throw some cash at you.  if I have to i will get a whole system, but seems a waste when I only have to get a control unit.

I found them. I must have tossed the EJ18, I have a 96 EJ25/EJ22 and 99 Phase II EJ25. 

[djellum]

ok thanks all.

just for reference I guess, swapping into a carbed dual range ea82 manual car.  im down with the 2.2, I just found this one years ago for dirt cheap next door.  it looks in great shape and was already pulled and palleted.  It was supposed to have the wiring complete but he couldnt find the ecm.  

tbh if I can find an ecm at a decent price ill just put it in and if it dies later i can do a 2.2 easy cause the swap is done, if I cant ill just refresh the ea82 until I can get a 2.2 complete

[el_freddo]

48 minutes ago, djellum said:

im down with the 2.2, I just found this one years ago for dirt cheap next door.

That’s how my first conversion started. Got an EJ20 for $100, then ended up getting an EJ22 engine, loom and ECU. Haven’t looked back. 

That EJ20 is now going towards another project. 

Cheers 

Bennie

[idosubaru]

2 hours ago, djellum said:

ok thanks all.

just for reference I guess, swapping into a carbed dual range ea82 manual car.  im down with the 2.2, I just found this one years ago for dirt cheap next door.  it looks in great shape and was already pulled and palleted.  It was supposed to have the wiring complete but he couldnt find the ecm.  

tbh if I can find an ecm at a decent price ill just put it in and if it dies later i can do a 2.2 easy cause the swap is done, if I cant ill just refresh the ea82 until I can get a 2.2 complete

I wasn’t suggesting an EJ22.  EJ18s are great, I’ve swapped them before and it’ll be great in an EA vehicle. Im suggesting to bolt an EJ22 intake manifold (and it’s wiring harness) onto the EJ18 engine and run an EJ22 ECU.  So keep and run your EJ18 but with EJ22 electronics that’s more available, and less convoluted than older EJ18 manifolds. 

[idosubaru]

pull a part yards if you have any. 

there’s nearly infinite intakes and ECUs here:
www.car-part.com 

[idosubaru]

To be clear - the EJ22 manifold bolts right onto the EJ18. Same manifold, bolts right up.

If the EJ18 doesn’t have a knock sensor (some don’t), the boss is there to accept one. They fail often enough I’d install a new eBay $5 one before a 25 year old used one. OEM would be great but they’re probably $$$.

Edited October 10, 2020 by idosubaru

[djellum]

Is there any operational benefits to the 2.2 intake?  Or just more common? Only 2 things ive heard mentioned are a knock sensor and egr deletion and im unsure what that might yield

[el_freddo]

5 hours ago, djellum said:

Is there any operational benefits to the 2.2 intake?  Or just more common? Only 2 things ive heard mentioned are a knock sensor and egr deletion and im unsure what that might yield

Ease of finding parts. Slightly more sophisticated engine management with the use of the knock sensor. 

EJ22’s are very common compared to the EJ18. Over here it’s much easier to find an EJ22 compared to an EJ18!

Cheers 

Bennie

[idosubaru]

19 hours ago, djellum said:

Is there any operational benefits to the 2.2 intake? 

Like I said earlier - no for a practical daily driver.  EJ18s were indestructible reasonable gas mileage beasts since day 1.  Theres no compelling reason to go out of your way.  

Us “purists” would put a little effort into the small improvements from an EJ22 intake/wiring since it’s easy at your starting point. It sounds like you really don’t care at all.  I’m all for EJ22 wiring/ECU, it’s like having a modern house with standard construction verses a cabin with odd windows spacing doors and trim.  but go with the EJ18 stuff and never look back. It’s minor and not a big deal. They have so few issues, if you did encounter something it would be minor  (notwithstanding any disclaimer about 25 year old engines in general)  

Go look for “EJ18” issues - it’ll be a long and boring search as you find it all but impossible to find any frequent issues. Some of this is from them being statistically less common, but whatever they’re beasts of an engine for longevity and reliability. 

Edited October 12, 2020 by idosubaru

[el_freddo]

The EJ18 would be even more bullet proof than the EJ22 - same bottom end, different bore diameter essentially, less power. 

Cheers 

Bennie

 

[idosubaru]

1 hour ago, el_freddo said:

The EJ18 would be even more bullet proof than the EJ22 - same bottom end, different bore diameter essentially, less power. 

Cheers 

Bennie

 

It is. But this discussion is about which ECU to use, not engine. OP already has the engine. 

[el_freddo]

On 10/13/2020 at 7:29 PM, idosubaru said:

It is. But this discussion is about which ECU to use, not engine. OP already has the engine. 

True, thanks for point that out to me.

I was adding to your comment as to why this may be: 

On 10/13/2020 at 7:33 AM, idosubaru said:

Go look for “EJ18” issues - it’ll be a long and boring search as you find it all but impossible to find any frequent issues. Some of this is from them being statistically less common, but whatever they’re beasts of an engine for longevity and reliability

Cheers 

Bennie

[idosubaru]

3 hours ago, el_freddo said:

True, thanks for point that out to me.

I was adding to your comment as to why this may be: 

Cheers 

Bennie

Right on beast, that was just to clarify for anyone not following the thread.  Carry on boss!