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EJ25 Swap Woes... *Updated* Forester ECU installed.


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Ok this is kind of a long story so I'm going to cram as much info in as little space as possible. I bought this car knowing it needed work. It started off as a simple head replacement and developed into a swap once I realized the rings on a few cylinders in the EJ22 had gone bad.

 

My car:

2000 Impreza Outback Sport Phase 2 EJ22 SOHC 5-Speed

 

My donor motor:

2001 Forester Phase 2 EJ251 Automatic.

 

ECU:

2000 RS EJ251

 

Engine harness is from the Forester motor.

 

I installed the 5-speed bits into the EJ251 and installed it. It would crank and crank but no start. Had spark, fuel and air but wouldn't turn. Read that the cam/crank triggers were different between my EJ22 and the EJ251 so I replaced my EJ22 ECU with one from a 2000 RS equipped with the same motor and the car fired right up, with a CEL. Driving the car was terrible so I gimped it to get the codes pulled.

 

Idle Air Control Solenoid

- P1512 (signal 2 circuit low input)

- P1514 (signal 3 circuit low input)

- P1516 (signal 4 circuit low input)

 

P1111 Atmospheric Pressure Sensor High Input

 

Symptoms:

Slightly rough idle

Hesitation/bogging under load (usually around 2-3k RPMS. If I put my foot into the gas it bogs, then takes off like a bat out of hell)

 

I replaced the IACV with a unit from a working car. With the new (to me) IACV the idle now surges between 1500 and 3000 RPMS. Hesitation is mostly gone while driving, but still present. Re-install "old" IACV and idle returns to an almost normal (still slightly rough) 900rpms and holds. Unplug either IACV and nothing changes, it either idles rough with the old one, or surges.

 

The car the ECU is from was equipped with the Atmospheric Pressure Sensor on the passenger side strut tower. The Forester from which the engine came from did not have the sensor on the strut tower from what I can tell so it must have been in the ECU as there is no wiring on the engine harness for one.

 

Last night I took a friend/fellow enthusiast out for a short drive since I was having trouble describing the issue. The car hesitated slightly at first, and then evened out and drove (seemingly) fine. Today I take the car to get the codes pulled again and it's the same old sluggish, hesitations under load. On top for that, this time I'm getting the same codes as above, plus these two oddballs.

 

P1116 - Torque down prohibition output (low)

P1722 - Automatic transmission Diagnosis Circuit High Input

 

This wouldn't be strange if my car/ecu was automatic. I understand Auto/Manual ECU's are the same aside from pinning, but can't figure out what would cause it to suddenly throw those codes all of a sudden.

 

Any thoughts how how to resolve these issues would be greatly appreciated. I've worn myself out reading threads trying to fix this with no avail :(

Edited by mycargoesvroom
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why aren't you using the forester ECU that matches the engine and the harness?

 

in my ECU / harness experience, which is limited to 95 - 98, the ECU needs to match the harness. if they move a pin on the ECU the harness wiring needs to match that so there is correct info communication between the ecu and the device / sensor. it is possible you would havew some CELs if all you had swapped was the ECU, not the engine or harness.

 

i don't KNOW that they made any changes between 00 and 01, but they could have.

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you probably could have swapped the forester engine with out swapping any thing else.

 

I did that at first and it wouldn't start with the EJ22 ECU. I had air, fuel, spark but no fire. I swapped in the ECU from the RS and it fired right up but of course with issues.

 

I'm thinking using a Forester ECU will fix it but I'm concerned about how the Forester ECU will work with auxiliary wiring in the body harness (IE Taillights, Headlights, windows etc).

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i don't think the ECU gets into any of the lesser wiring stuff.

 

the likely reason it did not start with the ej22 ECU is that they changed the cam sprockets at some point, apparently in 01. so when you swap an engine across that line you have to swap the ''original'' cam and crank sprockets onto your ''new'' engine. that way the original cam sprocket is talking to the original ecu. but you are way past that now.

 

do you have the forester ECU?? can you go back and get it?

or borrow one just to see.

 

EDIT: during an ej22 swap into a 98 obw i put a 96 L ECU into a 98 obw and the engine ran fine. but i had some, a couple of, false or ghost trouble codes. i spent several days tracking them down and finally got the correct ECU, no more CELs.

Edited by johnceggleston
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i don't think the ECU gets into any of the lesser wiring stuff.

 

the likely reason it did not start with the ej22 ECU is that they changed the cam sprockets at some point, apparently in 01. so when you swap an engine across that line you have to swap the ''original'' cam and crank sprockets onto your ''new'' engine. that way the original cam sprocket is talking to the original ecu. but you are way past that now.

 

do you have the forester ECU?? can you go back and get it?

or borrow one just to see.

 

I wish I did have it, would make things much easier haha. I just picked one up on ebay for $45 shipped. Thank you for your input, I really appreciate it. Everyone keeps saying "Just swap the timing stuff, IM, EJ22 harness on the EJ251 and call it a day". Although I know it's an option, maybe something I end up having to do. I'd really rather not. I don't get much time to work on the vehicle and a job like that could end up taking me a week.

Edited by mycargoesvroom
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You need:

 

EJ22 cam and crank sprockets.

EJ22 manifold.

EJ22 ECU

EJ25 long block.

 

The 2.2 ECU needs the proper cam and crank triggers to run. You need the 2.2's intake to match the car. Just use the 2.5 long block minus the timing sprockets and it will work without a problem.

 

You will never easily rid yourself of codes since you are trying to use an automatic ECU. Don't do that.

 

GD

Edited by GeneralDisorder
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You need:

 

EJ22 cam and crank sprockets.

EJ22 manifold.

EJ22 ECU

EJ25 long block.

 

The 2.2 ECU needs the proper cam and crank triggers to run. You need the 2.2's intake to match the car. Just use the 2.5 long block minus the timing sprockets and it will work without a problem.

 

You will never easily rid yourself of codes since you are trying to use an automatic ECU. Don't do that.

 

GD

 

Everyone keeps saying "Just swap the timing stuff, IM, EJ22 harness on the EJ251 and call it a day". Although I know it's an option, maybe something I end up having to do. I'd really rather not. I don't get much time to work on the vehicle and a job like that could end up taking me a week.

 

I'm not using an automatic ECU. I don't know why those codes randomly came up but they were not there originally, and they're gone now.

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GD is right. i mis-understood. i had just worked with someone who had swapped out the complete wiring harness for the engine bay and i thought this is what you had done.

 

the engine will run with the original ECU, intake and sprockets.

 

any stray CELs because of the trans swap you will have to live with or ground out the correct pin on the ECU to eliminate.

 

the forester ECU may work, but only if the wiring harness in the car (not on the engine) matches. this is a crap shoot. swapping the sprockets is for sure.

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GD is right. i mis-understood. i had just worked with someone who had swapped out the complete wiring harness for the engine bay and i thought this is what you had done.

 

That is what I did. Engine harness is from the EJ251 which was removed from a 2001 Forester.

 

the engine will run with the original ECU, intake and sprockets. [/Quote]

 

I understand that. But as stated before I'm trying to avoid being without a car for another week or two while I slowly find time to swap everything out. The purpose of my thread was to hopefully get some confirmation that the ECU would indeed work, which you originally suggested it might.

 

any stray CELs because of the trans swap you will have to live with or ground out the correct pin on the ECU to eliminate.

 

I didn't swap transmissions and the ECU I'm using is from a 5-Speed RS. I've driven the car and I have no idea why the ECU was looking for a TCU.

 

the forester ECU may work, but only if the wiring harness in the car (not on the engine) matches. this is a crap shoot. swapping the sprockets is for sure.

 

I was on the fence about buying the ECU for that very reason. If it doesn't work, well then I know.

i don't think the ECU gets into any of the lesser wiring stuff.
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I understand that. But as stated before I'm trying to avoid being without a car for another week or two while I slowly find time to swap everything out. The purpose of my thread was to hopefully get some confirmation that the ECU would indeed work, which you originally suggested it might.

 

 

 

A week or two to change a timing belt? Are you kidding?

 

It can be done in about 2 hours.

 

You'll spend more time screwing around changing ECUs. And I'd be weary of plugging random ECUs into your car.

 

Some of them use the same connectors, with different wiring configurations. You could end up shorting something out.

 

 

We have all told you, use your cars Intake, Cam and Crank gears, and ECU. Anything else is a crapshoot, unless you spend alot of time researching ECU pinouts.

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A week or two to change a timing belt? Are you kidding?

 

It can be done in about 2 hours.

 

You'll spend more time screwing around changing ECUs. And I'd be weary of plugging random ECUs into your car.

 

Some of them use the same connectors, with different wiring configurations. You could end up shorting something out.

 

 

We have all told you, use your cars Intake, Cam and Crank gears, and ECU. Anything else is a crapshoot, unless you spend alot of time researching ECU pinouts.

 

It's not just changing a timing belt. I'm sorry I don't have even 2-3 hours at a time most days to dedicate to working on it. I'm a stay at home dad actively searching for employment so my time is very limited. I was simply looking for an alternate solution to save me time and get my car on the road as soon as possible.

 

With all of this said, will I need to purchase a new tensioner?

Edited by mycargoesvroom
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It's not just changing a timing belt. I'm sorry I don't have even 2-3 hours at a time most days to dedicate to working on it. I'm a stay at home dad actively searching for employment so my time is very limited. I was simply looking for an alternate solution to save me time and get my car on the road as soon as possible.

 

With all of this said, will I need to purchase a new tensioner?

 

Thinking about it now.....I'm pretty sure only the Crank wheel is different.

 

It really is just a timing belt......take off the belt.....slip the crank gear off, slip the new one on.

 

No NEEED to change tensioner or idlers, or even the belt......except that if your in there and can afford the parts its a good idea.

 

But to just "git'er done" and running, the crank gear is all you need to swap.

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so let me get this right.

 

you swapped the engine and it did not run

you swapped the wiring harness that connects to the ECU, it did not run.

and you swapped in the ECU from a different car altogether, and it runs but with issues and CELs.

 

right so far?

 

if this is true, and the forester ECU is an exact match for the engine and the harness, that should do the trick.

 

if any of this is an error pleas make the correction.

 

the ECU must match the wiring harness it is attached to. when they make a change in the ECU pin out, they have to change the harness to match. other was it does not communicate correctly.

 

on a side note, it is the wiring harness that makes the ECU look for an auto trans TCU. the manual trans harness grounds out a pin on the ECU. this tells the ECU not to look for the TCU. your forester harness was in an auto trans car, right?

 

if the above info is correct, your shortest quickest solution is the matching ECU.

 

if you had contacted us when you started, we could have saved you a butt load of work.

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Yes John, you're mostly correct.

 

The engine harness was still on the EJ251 when I bought it, so when the EJ22 came out with it's harness, the EJ251 went in with its harness. That is the ONLY wiring that is not original to the car. The harness that plugs in to the engine harness from the ECU has not been altered in any way.

 

I don't know why I didn't think about the harness coming from an Automatic, which makes perfect sense.

 

if you had contacted us when you started, we could have saved you a butt load of work.

 

Haha I actually tried. I signed up for an account here a week before I bought the engine but wasn't able to post anything :(

 

Edit: Reading through my posts I realized I may have come off a little arrogant. I've been overloaded with mixed information and my frustration with the situation is leaking out at you guys. It wasn't my intention at all and I apologize if it seemed that way.

Edited by mycargoesvroom
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well, you can try the forester ECU , but there is no guarantee it will work. if they made a change in the 01 ECU it will have issues with the wiring harness that the car connects to. but unless they made major changes chances are that the engine willl run even if it has stray CELs. but it may not improve any over what you have now.

 

the harness on the engine may / will be ok if the ECU works.

 

but if the ECU does not fix things, your only solution is to do as GD said. this will get it running for sure. and the cam and crank sprockets can be had used for less than the forester ECU. and the work will not take that long. and you do not have to replace anything except the 2 sprockets. all the other parts will work just fine.

 

note, if you are close to the timing belt change interval you might consider replacing those parts as well.

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Forester ECU came in today and although I was 100% sure it wasn't going to fix my issue (I'd actually convinced myself it probably wouldn't even start), I put it in. Well to my surprise she started right up again. I hopped in and drove about 2 miles to get the codes checked and she drove smooth as butter, no hesitation, no bucking, nothing that I could feel out of the ordinary.

 

Checked the codes and no surprise I got the same codes as before. So I erased the codes, reset the ECU and hooked it up again. This time I only got 1 code, 1516 (same as one from before). The only thing notable other then that is that it DOES NOT like having the A/C on. When cruising it's fine but as soon as you push the clutch in she wants to bog down and die out. I'm assuming that has something to do with the IACV not functioning correctly.

 

I'm still going to change the timing stuff I just wanted to report how the car reacted to the Forester ECU.

Edited by mycargoesvroom
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What intake did you use? If you used the 2001 Automatic intake, that could be the problem. 5 speed uses a different idle air controller than the 4EAT does.

 

wondering if thats your issue. both IACS will bolt up, but there is differences between the two at least in the Gen 1 EJ18 and EJ22

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