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Can you run an NA EJ201 from an NA EJ22 ECU and wiring etc??

PostPosted: Sun Jun 17, 2018 11:09 pm
by RObErT_RaTh
Hello fello suby owners! Hopefully there's some Liberty experts out there who know their EJ22's like the back of their hand??? :)

This request is regarding Australian versions of the EJ engines only (USDM etc wiring diags are not what I'm after unless they match but not from what I've seen)

I know it's a strange request but to keep a long story short I have to try and get my EJ201 2.0L SOHC (1998 GF8 Impreza GX Auto naturally aspirated) to run using an EJ22 ECU and associated additional wiring/sensors that may be required. Specifically thinking of using EJ22 electronics from an early 90s liberty that I can grab parts from upullit etc. Is it possible? 2.2L computer running 2.0L engine?

REASON: I need an engine that runs a MAF (Mass Air Flow) sensor, instead of a MAP (Manifold Absolute Pressure) sensor so that I can "legally" run an NA > Turbo conversion car. The MAP sensor won't handle boost (from what I've read/seen) without aftermarket items fitted and therefore can't legally rego and use as my daily driver. The MAF sensor / EJ22 can run small boost (stock TD04 ~8psi) and won't get me in trouble with the letter of the law. This is a daily driver and all original functions of the car need to be 100% working.

Basically I need to know if it's going to be possible to wire in a MAF sensor and the EJ22 ECU to my existing wiring and what sensors will or won't be compatible (TPS, knock, cam position, crank position, O2, IACV etc) and it has to work with my auto trans, immobiliser and whatever else may cause an issue??? Ideas? Have I missed something major that would make this impossible? I already have ALL items sourced to do the turbo swap but with aftermarket fuel pressure device it would not be legal and therefore I've had to come back to the drawing board.

I am yet to locate a wiring diagram specifically for a 100% for Australian EJ201 NA SOHC MAP sensor engine and without these ECM/ECU pinouts and associated connections I guess I can't even be sure of what I'm starting with in terms of connections let alone what I'll need to end up with in order to have the EJ22 computer happily run a lower capacity motor and then add boost as well! I've ordered a service manual for the libertys which should help me with the wiring on that end but looks like I might have to contact subaru for wiring on my impreza side of things.

If anyone knows if position sensors (and triggering types?) will totally be incompatible or if something else major I haven't realised will prevent this from working please let me know and I'll stop now but if not I'd really appreciate any helpful info or feedback that could see this idea actually work. Thank you!

PS, if all goes well in theory hopefully I can get the EJ22 electronics etc for < $200 and get the car actually running and working 100% as NA first and then add the turbo once I'm happy the engine runs fine with it's new brain.

Re: Can you run an NA EJ201 from an NA EJ22 ECU and wiring e

PostPosted: Thu Jun 21, 2018 3:41 pm
by Shaheenis
Your post is a lot to unpack and I can't help but think you are creating a lot of work and problems for yourself when there would be a simpler way.

This is only a guess based on not knowing the actual answer. An NA EJ22 ECU will not be suitable to run a turbo. It should be suitable to run an EJ20, I actually run the opposite in turbo form - I run an EJ22 with turbo on an EJ20T ECU and besides the capacity, the engines are the same.

Hopefully someone else who has the knowledge fresh in their heads will respond.

Good luck!

*EDIT* I also think you would have better luck in the RSLiberty forum (http://www.rslibertyclub.org/forums/)

Re: Can you run an NA EJ201 from an NA EJ22 ECU and wiring e

PostPosted: Tue Jul 17, 2018 1:16 pm
by RObErT_RaTh
Shaheenis wrote:Your post is a lot to unpack and I can't help but think you are creating a lot of work and problems for yourself when there would be a simpler way.

This is only a guess based on not knowing the actual answer. An NA EJ22 ECU will not be suitable to run a turbo. It should be suitable to run an EJ20, I actually run the opposite in turbo form - I run an EJ22 with turbo on an EJ20T ECU and besides the capacity, the engines are the same.

Hopefully someone else who has the knowledge fresh in their heads will respond.

Good luck!

*EDIT* I also think you would have better luck in the RSLiberty forum (http://www.rslibertyclub.org/forums/)


I know it's a lot of work but in order fit the requirements of 'affordable' and 'legal' it's really the only option that I can see. My easier way with a Holley FMU (which I already own) will handle extra fuel when it detects boost but these aren't legal in a street car here :(

I have read several articles written by people that have stock NA EJ22 motors and they turbo them on stock ecu with low boost, here's just one example so it is possible and been done several times before: http://www.automersion.com/2015/05/turb ... baru-ej22/

So you had a stock NA EJ22, added a turbo, running from stock EJ20T ECU and all good without tuning etc? Isn't the EJ22 SOHC and the EJ20T motors DOHC?? I would LOVE to hear more about your setup and how you got it working because running an EJ20T ECU could be an option for me but I thought it wouldn't be possible with the different cams etc.

Also based on the lack of responses here I think you might be right about checking out RSLiberty forum, thank you. But please tell me more about your setup, thanks!

Re: Can you run an NA EJ201 from an NA EJ22 ECU and wiring e

PostPosted: Fri Aug 03, 2018 2:29 pm
by Shaheenis
So you are correct, my EJ22 had turbo heads fitted to it from a MY97 WRX EJ20T which a DOHC. You could use any turbo heads. I only used the EJ22 block/case and crank as it was a new build I used forged pistons and rods, new bearings, new head gaskets, new case bolts and seals and and new head studs. The crank is the same as turbo. The EJ22 block does not have piston oil squirters but this isn't an issue. You could use the stock EJ22 block untouched for a low boost application. As I used EJ20T heads I used the recommended EJ255 triple layer steel head gaskets (1.6mm from memory). I ran this with the stock Turbo ECU and stock 380cc injectors (also worked fine with 440cc yellow tops). You need to match injectors and ECU. I ran stock boost with stock boost control, no tune no nothing else added. IT had bigger plans for 20psi and after market ECU but I never went there. Runs a smallish VF28 BB turbo from a early STI rex.