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Short version: When I hook up the NA ECU with the harness pinned as NA, the car will start and run for 10-15 seconds. When I hook up the turbo ECU with the harness pinned as turbo, I get nothing. Any ideas?

Long version: I got a '92 Legacy for free, because it had a bad tranny in it, so I figured I would build an EJ22T. I found all the parts for a NA-T swap (ECU, heads, turbo, exhaust stuff, sensors, etc.). So I swapped all the turbo stuff on. Installed the engine, and got all the wiring done.

I plugged in the NA ECU first to see if it would start. It started right up, ran for 10-15 seconds real smooth, then just quit. Only code was 49, which is improper MAF sensor, since the turbo MAF sensor is hooked up.

I thought maybe the NA ECU was bad, so I repinned the harness to turbo (swapped cam/crank sensor pins at ECU, added in the turbo sensors, and that's it). When I turn the car to ON, I get nothing. No check engine light, no FP relay. The main relay clicks though.

Any ideas at all what is going on here? It's almost like the turbo ECU doesn't get any power for some reason. I have two turbo ECUs, and neither of them work. The NA ECU still works fine though (except for the harness being pinned as turbo). Any help is greatly appreciated.

Thank you,
-Jason

You need to swap the positive leads for the cam & crank sensors. They're reversed. Here's the ECU I-O

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

I'd suggest doing a search as myself and others have done the swap. There's more details in the threads about all the specific stuff that needs to be done.

Thanks for the reply. I swapped all three cam/crank pins, instead of swapping just the positives. Would that be the issue? I searched and found a few threads, but the cars were able to start for some amount of time, I can't even get the CEL to turn on, or FP to click. It's like the turbo ECU is pinned differently for power (but I know it's not).

Thank you,
-Jason

Legacy777 wrote:You need to swap the positive leads for the cam & crank sensors. They're reversed. Here's the ECU I-O

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

I'd suggest doing a search as myself and others have done the swap. There's more details in the threads about all the specific stuff that needs to be done.

Also if it matters, the free donor car was an auto, and i swapped it all into a 5spd.

Hi Jason,

I'm going to post the email I sent you here so other people can follow along.



The first thing I’d suggest is to double check your wiring. Are you sure you swapped the crank & cam pins correctly? It shouldn’t matter that you swapped all three pins vs. just the positive pins.

The only other comment I can tell you is that the 92 may have some different wiring for the non-turbo cars. I know this only to be a fact for the MT/AT identifier pin. It is wired backwards from what the factory manual states. This leads me to believe that there could be a possibility of other wiring differences, but without checking every single pin on the ECU, that’s only speculation.

My recommendation at this point is to do just that, check every single pin at the ECU and verify it goes to what the wiring diagrams say it goes to. If you haven’t run across it yet, here’s the FSM for the 92 Legacy.

http://www.main.experiencetherave.com/s ... and_Elect/


Also, I’ve attached an excel file with the ECU I-O. This list shows every pin on the connector and what is there. This list is what I personally verified on my car as to being correct. So really what you need to do is just go down the list with an multi-meter and check all the wiring and make sure each pin is going to where it should be.

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

Thanks Josh. I'll also update as we find solutions.

FWIW, did you try an NA JECS MAF w/the NA ECU? Obviously the NA ECU won't have the proper fueling/ignition when in boost, but might be useful for diagnostics.

I'm not going to comment on the Turbo ECU as that is Josh's domain.

Also, the Turbo ECU is the same for 5-speed and AT.



GL,
Td

The car shouldn't work period due to the cam/crank sensors being backwards between the n/a & turbo models.

I think we may have figured out that the issue is due to how he had the self shutoff circuit wired. He was going to check that and let us know.

Sorry for the late reply, got busy with the holidays. Anyway, as Josh stated, it was how the main and FP relays were wired. I had the relays wired to come on with switched +12v, instead of through the ECU. Once I wired the relays correctly to the ECU, bam, it runs.

Thanks all.

-Jason