legacycentral bbs

1992 Legacy sport sedan, run off factory 22t PCM and wiring harness. Engine is a mostly stock ej20g from a first generation legacy RS.

Any input? The only diagram i found is on the apexi website with lists is for a 20G (F2-B)
http://www.apexi-usa.com/content/pdf5483.pdf

Ive heard rumors that this is the correct diagram to use for 22T ECU but i do not want to fry out the PCM.

Any other tricks + tips for the install?

Thanks !

use that only if you're using a 20G ECU, if you are using a USDM 22T ECU use the picout from

http://www.surrealmirage.com/vrg3/ecupins/

From what I can tell the F2-B wiring diagram is correct, and references the correct pinouts on the EJ22t ECU. For your reference, here's the ECU I-O for the 92 Legacy.

http://main.experiencetherave.com/subar ... CU_I-O.zip

I'd suggest using T-taps to tap into the stock ECU wiring. I hate the other alligator tap setups.

http://www.shop3m.com/80014000832.html

You can search on google for electrical t taps and probably find another place to buy a smaller number.

Apologies for being a newb, but with the purple wire, if i use this to monitor injector duty cycle instead of RPM, will that hinder the AVCR's ability to control boost? Or is this wire just used for monitoring?

Another quick question (maybe not so quick)

I installed the AVCR this morning. Should i have left the factory subaru boost sensor there? I removed it completly and now am using just the apexi. I have it set up as show in the manual, but the car wont build more than 4 PSI in any gear. When it hits 4 PSI it hits some sort of fuel cut and the car starts bucking.

A friend said that since i removed the factory pressure sensor, and the check engine light came on, that i could be in limp mode?

How do i install the AVCR and not have a CEL. The car runs great, just doesnt boost.

Anybody have an installed avcr they would like to share their settings with? ill make it worth your while

You can either leave the factory BCS plugged in and not hooked up to any vacuum, or you can get a "dropping resistor" from any Auto 1st gen Legacy (located on front passenger strut tower) and plug it in to the BCS plug. It has the same connector and plugs right in and gets rid of the CEL.

Almost fur sure your BCS being unplugged is causing the issue. I had an ECU with a bad BCS circuit in it that had the exact same behavior.

Thank You! I will head out tommarow morning and hook up the factory BCS and hopefully all is well!

Did you unplug the boost (pressure) sensor or the boost control solenoid? Eitherway, as Alphius mentioned you need to keep the factory sensors plugged in, even if they're not being used.

As for the purple wire, I think it's mainly just an informational type thing and may be used by the unit for advanced boost control options. Which one did you tie into, injector or engine rpm?

Engine RPM for now. Spent a good hour or so setting it up yesterday and shes running like a champ @ .85 bar.


Thank you very much for all your help BBS, really makes working on these cars much easier.

Nice! Glad it worked out for ya.