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obd1 to obd2 swap questions 93 legacy running v8 sti ecu

Posted: Thu Mar 28, 2013 12:44 am
by nosyt
I decided this year i was going to build a proper motor for my wagon. currently its a ej22t running dohc heads with jdm sti cams and valve springs. 550 injectors td05 on a robtune

with my goal of bigger numbers and proper tuning im wanting to go obd 2.
i picked up v8 jdm sti heads with intake avcs, equal length header, oil pan, twin scroll turbo, downpipe, intake manifold with sensors and throttle body, wiring harness and ecu

just wondering if anyone who has done a swap can chime in with any issues i may run into
does the ecu need an electronic speed sensor or can i keep my cable for my cluster?
for oil pressure and coolant temp do i keep the stock sensors for my cluster and just run the one coolant temp sensor for the ecu?

the block this is all going onto will be a eh22t with scat h beam rods wiseco .020 forged pistons and arp head studs

Re: obd1 to obd2 swap questions 93 legacy running v8 sti ecu

Posted: Thu Mar 28, 2013 3:33 am
by mike-tracy
I'm not too knowledgeable about this swap (although I'm currently swapping one into a USDM WRX!) but if no-one knows the answer I suggest pm'ing Brian from Iwire, as he's the man with cross generational swaps. He's not a member on here to my knowledge.

Re: obd1 to obd2 swap questions 93 legacy running v8 sti ecu

Posted: Thu Mar 28, 2013 4:16 am
by subaru_styles
why not just run a pnp full standalone, then configure for the new sesnor timing

Re: obd1 to obd2 swap questions 93 legacy running v8 sti ecu

Posted: Thu Mar 28, 2013 5:57 am
by BiNiaRiS
I'd love to see what route you end up taking with this. I'm on a PP6 right now but know doing an OBD2 swap or full stand alone will allow me to go with some beefier options. So far PP6 seems pretty decent though.

I'll keep watching this ;)

Re: obd1 to obd2 swap questions 93 legacy running v8 sti ecu

Posted: Thu Mar 28, 2013 5:43 pm
by MikeyMeyagi
im going to be using my PNP hydra 2.6 with my 257 swap if i ever get around to installing it.

Re: obd1 to obd2 swap questions 93 legacy running v8 sti ecu

Posted: Thu Mar 28, 2013 5:44 pm
by Legacy777
You can still keep your gauge cluster and all that. It outputs an electronic signal to the ECU. You may need to swap cam & crank sensors to match whatever is appropriate for the timing pullies/gear.

For the most part I think all your older sensors should be ok. There may be a couple you'll have to swap out. The challenge is going to be the wiring, and additional sensors that are there on the OBD2 cars, but not OBD1 cars. For example fuel temperature, and anything else that may be missing. Ultimately, it's not too hard to swap over to the newer style part which has those sensors, but then you've got to do the wiring and add all the additional inputs.

I think this is doable, but you certainly need to do your homework up front and figure out exactly what the ECU inputs & outputs are for both the OBD1 ECU you're currently running, and the OBD2 ECU you want to run. As mentioned, some stuff will map right over in terms of compatibility, but until you do a more thorough search or analysis, you won't know for sure what all you're going to have to add and modify.