Jump to content
Ultimate Subaru Message Board

OBDI EJ18 in place of a OBDII EJ25


Huck369
 Share

Recommended Posts

Like the title says, I was thinking about installing an OBDI EJ18 in place of a OBDII EJ25 any info on this?

I'm doubting it will just "plug and play" but what will it take to get it done.

 

...and yeah, my internet time is limited, and there are tons of swap threads to sift thru when doing a search, so, if you don't want to answer something that has already been answered, please link me to a relevant thread, and I'd be very thankful.

Link to comment
Share on other sites

Huck - call or email me, I've done it. It's easy. You even saw one of the cars I did it too a couple years ago when we hung out in Cinci.

 

It will depend on which EJ25 you mean?

 

Option 1: (this will only work with DOHC EJ25's):

Get a 95-99 EJ22 intake manifold with EGR. Those bolt up to the EJ18 and are plug and play into the EJ25. The EJ18's I've seen have EGR...and 95-99 EJ25's have EGR so you'll want an EJ22 intake manifold with EGR. EJ22's are a crap shoot, some have EGR, some don't..and sometimes there's no rhyme or reason.

 

EJ18 are dual port heads so the EJ25 exhaust bolts right up.

 

Option 2:

The other option you could do is to probably bolt the EJ25 heads up to the EJ18 block, then you wouldn't have anything to worry about - same heads, intake manifold, etc. I've never checked valve clearance, like if the EJ25 valves would strike the smaller EJ18 cylinder walls...shouldn't be too hard to check that. I know you can bolt the EJ25 heads to the EJ18 block.

 

Cost wise I guess you want to see if you can get an EJ22 intake for cheaper than a pair of headgaskets - might be about the same.

 

I suspect you're selling it so it won't matter but if I was keeping it I'd opt for the EJ22 intake so compression doesn't get hammered and ease/cheap maintenance - cheaper timing components, fewer cam seals, no nearly impossible to adjust DOHC valves.

 

If you're talking about Phase II SOHC EJ25's then option #2 is your only option.

Link to comment
Share on other sites

First question. What year 1.8? Does it have EGR or ODB2?

 

I ask to confim because the only 1.8's I know have no EGR and that a problem if you need the CEL to be out.

 

as the title says, it's an OBDI EJ18, I think a 95 model...would have to check about the EGR, but could live with the CEL if it'd get it back on the road.

Link to comment
Share on other sites

I assume you could do the same that I did with a 2.2 last summer.

 

'94 2.2, in a '96 outback. Pulled the intake manifold off both motors, and swapped the engine harness between them. The important stuff (injectors and such) plugged right in, and I swapped all the vacuum lines and solenoids to recreate the 2.5 setup on the 2.2. I also had to swap the throttle bodies as the plug for the harness was completely different.

 

 

It runs awesome! I meant to swap an OBD II 2.2 ECU in it, but never got around to it. With a complete longblock, I was able to do it with no new parts except gaskets (IM and TB).

Link to comment
Share on other sites

'94 2.2, in a '96 outback. Pulled the intake manifold off both motors, and swapped the engine harness between them. The important stuff (injectors and such) plugged right in, and I swapped all the vacuum lines and solenoids to recreate the 2.5 setup on the 2.2. I also had to swap the throttle bodies as the plug for the harness was completely different.

 

QUOTE]

 

Just an observer but please clarify for others that may see this.

 

It makes it sound like you put a 2.5 intake onto a 2.2 or 1.8 to me and in my experience that WON'T work. I hear it will with the stuff after 2000 or so though.

Link to comment
Share on other sites

there is a differance in the idle moters from 1.8-2.5 but the rest is perty mutch the same might take some doing i would put 2.2 heads and intake on your 1.8 thiss will interchange better or just a 2.2 intake if you can find the same year gessing 96-97 2.2 will have the harness that plugs right in you may even get one with egr port the 1.8 with turbo 2.2 heads and turbo setup works good with no mods to bottom end the bigger combustion chambers makes for good low budget turbo engine cheers

Link to comment
Share on other sites

Should have clarifed in the original post, the vehicle is a 99 Forester with the SOHC 2.5, and I have 3 EJ18's laying around...

 

Numbchux I may try that, sounds pretty straight forward.

 

Got one more thing to try to get the 2.5 usable, but if that fails, I'll probably be giving the EJ18 a shot.

Link to comment
Share on other sites

'94 2.2, in a '96 outback. Pulled the intake manifold off both motors, and swapped the engine harness between them. The important stuff (injectors and such) plugged right in, and I swapped all the vacuum lines and solenoids to recreate the 2.5 setup on the 2.2. I also had to swap the throttle bodies as the plug for the harness was completely different.

 

 

Just an observer but please clarify for others that may see this.

 

It makes it sound like you put a 2.5 intake onto a 2.2 or 1.8 to me and in my experience that WON'T work. I hear it will with the stuff after 2000 or so though.

 

Key phrase "and swapped the engine harness between them". You are correct, the intake manifold will not swap, but the manifold has to be removed to swap the wiring harness.

Link to comment
Share on other sites

Key phrase "and swapped the engine harness between them". You are correct, the intake manifold will not swap, but the manifold has to be removed to swap the wiring harness.

 

This is what I was gonna say too.

 

Take the EJ25 wiring harness (probably throttle body too) and swap it over to the EJ18 manifold.

 

Biggest issue will be IAC. If nothing else you can cap it and you'll just have to hold your foot on the gas to idle it up for a few seconds when cold.

 

Just an FYI it will be alot slower with an EJ18, and if too heavy a car you won't ge that much better milage if you try to give more gas to go as fast as it would have before. Let it be slow, and you'll save.

Link to comment
Share on other sites

This is what I was gonna say too.

 

Take the EJ25 wiring harness (probably throttle body too) and swap it over to the EJ18 manifold.

 

Biggest issue will be IAC. If nothing else you can cap it and you'll just have to hold your foot on the gas to idle it up for a few seconds when cold.

 

Just an FYI it will be alot slower with an EJ18, and if too heavy a car you won't ge that much better milage if you try to give more gas to go as fast as it would have before. Let it be slow, and you'll save.

 

Not looking for better MPG, just the cheapest replacement motor (I have 3 EJ18's laying around) I figure the 4.44 gearing in the Forester will make it "OK" for hauling it around,but yes, I know it will be slower than the 2.5....but faster than a blown 2.5 ;)

Link to comment
Share on other sites

i put the single cam heads on 2.2 s all the time but on the 1.8 i think the valves hit the inside of the barrel the throttle body will not bolt up from 2.5 -1.8 i would be looking for 2.2 bottom end for your car

 

 

 

2.5 Throttle body will bolt right onto the EJ18 (or an EJ22) throttle body. IF it's a Phase II 2.5 you will need to make a blockoff plate to go between to cover the IAC opening in the corner. It can absolutely be done with no more fab than cutting a thin plate off steel or aluminum.

 

Also, not to flame, but something I've been noticing from you for a while. I think we would all understand your posts more if you used some punctuation. Your posts tend to be a single long run on sentence. It helps with the communication on the board.

Link to comment
Share on other sites

2.5 Throttle body will bolt right onto the EJ18 (or an EJ22) throttle body. IF it's a Phase II 2.5 you will need to make a blockoff plate to go between to cover the IAC opening in the corner. It can absolutely be done with no more fab than cutting a thin plate off steel or aluminum.

 

My work with EJ18s is limited (even though I own one :o ). But I'm pretty sure....the bolts for all EJ TBs are the same configuration.

 

http://opposedforces.com/parts/info/16175AA150/

TB gasket. I found many different part numbers, but they overlap. This one lists all years of the 1.8, and I many years of the 2.5.

 

Also, not to flame, but something I've been noticing from you for a while. I think we would all understand your posts more if you used some punctuation. Your posts tend to be a single long run on sentence. It helps with the communication on the board.

 

agreed. I think I understand about 10% of what he says.

Link to comment
Share on other sites

Huck - I checked, I don't have the EJ18 intake any more but I do have a spare 2000 Forester manifold which has the same idle set up (i checked) as your 99.

 

I could ship the throttle body with the solenoid/idle controller on it if you want to compare it to your EJ18 intake. Let me know if you want those parts to play with so you don't have to disassemble that EJ25.

 

If Gloyale is right that a SOHC throttle body will bolt up to the EJ18 then that would be awesome.

 

The Forester idle controller has a solenoid in the throttle body with a hose going to some contraption up front. The hard part is that this contraption is somehow tied into a bunch of the evaporative lines and some other metal line that taps into the intake right below the fuel injectors. Weird. Anyway, not sure how you would route all that.

Link to comment
Share on other sites

copy. wish i had one of your EJ18's, i might try it on a forester i have sitting here. LOL

If you wanna come and get one, it's yours.

It's been out of the car for a few years, but been in a shed.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...