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Frankenmotor tuning


czny
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Here's my list of building blocks:

 

90 Lego OB ej22e heads

Delta RV cams

99 Lego OB ej25 block

90-91 Lego 22611AA563 ecu, MT

99 Lego OB y-pipe or OBX UEL SS headers

90 Lego OB eng wiring loom & interior loom

 

Granted OBD 2 is now the preferred system to harvest for this, I'm attempting to stay within the 5 yr span according to Calif ARB guidelines to make my swap smog legal. My 87 gl can have up to 92 OBD 1 without the arbitrators/inspectors throwing a hissy fit.

 

My question is would a 92 Lego intake manifold with throttle body have better IAC adjustment than the 90 Lego OB manifold?

 

Just in case I need to bump up the idle speed to compensate for higher compression & RV cams.

 

Edit: read mellow65's post, Swapping a phase 2 ej25 in an older legacy or impreza, in USRM, Engine

And fairtax4me's post, IAC and TPS explanation, in Engine electrical

Edited by czny
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Found more info about IACs at NASIOC:

http://forums.nasioc.com/forums/showthread.php?t=1752404&highlight=92+lego+iac

 

Found a complete 92 Lego intake w throttle body, injectors, loom, etc for less than local PAP prices.

 

My question is:

Would a 92 Lego intake manifold with throttle body have better IAC adjustment than the 90 Lego OB manifold?

 

Some insight would be appreciated.

Thanks!

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Use a Computer that matches the harness and intake.

 

90,91 Legacies, with Manual trans had a 2 wire "open only" IAC (single coil)

 

Auto trans, and all later legacies used a 3 wire, "open/close" type (dual coils)

 

I would recommend using a 92 ECU, harness and intake if you can find it.

 

 

This would let you use an IAC from any 92-98 2.2 or 2.5

 

Also, the 92 fuel injectors interchange with the 2.5 ones.....90,91 don't.

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To presslab:

 

I've read & re-read these a few times. Great topics.

Just asking questions before I do the build & meld the wiring in my 87 gl.;)

 

To Gloyale:

I've been combing the serve yourself yards for intact 92s like your suggesting, but, most of the time essential items already have been removed, or destroyed.

 

Thanks to both of you!

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If you're not going to fix the root of the problem and just want to raise the idle speed, you can just turn the large hex on the bottom of the idle valve to let more air through. At that point you'll be fighting the ECU, because it will be trying to lower the idle speed by closing the solenoid valve. So it doesn't really matter what kind of IAC solenoid you use.

 

Without tuning, my motor ran super lean at idle with the cams. I doubt you'll pass smog like this.

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I have on hand 3 ECUs so far:

 

90 Lego AT, 22611AA381(donor ej22 engine)

 

90 Lego OB MT, 22611AA560(donor ej22 wiring looms including to ECU)

 

90-91 Lego OB MT, 22611AA563

 

The last one is E7, not the F9 designation. I did figure that the Frankenmotor as built would fail smog without remapping. Will have to read further & learn more about the opensource tools.:cool:

Edited by czny
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22611AA563 has a 32 pin blue ROM board socket next to the ROM. "ROM board" is printed on pcb next to skt.:)

Noticed the ROM designation MECF-M04 is same as on outside tag. Hmm.

 

22611AA560 has blue skt also. ROM is MECF-M01, same as outside tag.

 

22611AA381 (AT) has none of these features. Must be the "dumb" 89-90 ECU.

AA563E70924A2MECF-M04004.jpgAA563E70924A2MECF-M04001.jpg

AA563E70924A2MECF-M04009.jpgAA563E70924A2MECF-M04007.jpg

 

The 563 has this on the ROM:

MECF-M04

H4BLAP3

A

 

Socket pin 1 is next to ROM, RH corner. All pcb traces go directly from socket to ROM. Must be the one.

 

BTW, these AA560 & AA563 ECUs are Hitachi. Looked at your ECU presslab & noticed a very different layout.

Edited by czny
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  • 2 weeks later...

After a LOT of reading here & other forums, decided to go with a 96 Lego OB OBD2 system. Harvested a ej22, 5mt, awd intake complete with injectors, IAC, TPS & wiring harness. Pulled dash then front harness including fuse boxes & ECU from alternator through fender across behind dash to rt footwell. Very few cuts made.

22611AC431, 7B ECU. No EGR at all.

Figured the cam overlap would create enough charge dilution with exhaust. No need to compound it with EGR controls.:-p Ha ha ha.

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