Swapping in an OBD2 gsr motor into a OBD1 LS
 

My integra is a 95 with 203,000 Kilometers.

I found a good deal on a obd2 gsr motor+tranny with 180000 kilometers. I am wondering what I need to complete the swap.


I know I can plug in my stock harness into the GSR motor for the most part.

I know I will need an obd1 p72 ECU

I know I will need a jumper harness for the distributor since it is OBD2. I am wondering if I can just re-wire it? What I mean by this is go to the junkyard, find an OBD2 integra and cut off the plug that would have gone into the distributor and rewire my 2plug engine harness for the dizzy into a 1plug for the obd2 dizzy. If I do this, can you let me know if it has to be vtec or not? Im assuming the plugs are the same.

seems as if this question is answered in this thread so I will just get a single plug for a junkyard harness and wire it myself

I need to run 4 wires. Vtec pressure, oil, knock and butterfly (gsr manifold). Do I need to wire anything else? Does the obd2 motor have anything else that I can ignore? Maybe a crank angle sensor? Or if its OBD1, can I ignore the knock sensor? I know obd2 has 2 o2 sensors but this wont affect me?

I have read around, but most people are swapping OBD1 gsrs into their ls motors, or in civic chassis, and its getting confusing. Thanks

Also, Tips on axles? half shaft? Injectors? Alternator? I'd like to keep the motor OBD1

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Option 1: Find an OBD2 GSR harness. Everything will plug in (including injectors, alternator and distributor) and it'll plug into your shock tower harness. You'll still have to manually wire in VTEC/Knock/IAB's to the ECU.

Option 2: Reuse your engine harness. Manually wire in VTEC/Knock/IABs. Reuse your distributor and injectors. Either find a DOHC VTEC Bseries distributor or use a jumper harness for it to use the OBD2 distributor. You could probably use the distributor you have for the LS motor but all the mounts won't line up.

With the P72 you'll have to wire up knock but not the CKF sensor by the crank. I believe you can use your axles as well.

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

you can also get an aftermarket single runner intake manifold so you dont have to wire in the iab

and get your ecu chipped (enable vtec and a chip with gsr basemap) xenocron has alot of basemaps they most likely have a basemap for a gsr with single runner intake as well.

if you do go with an ITR replica manifold you can use a b16 harness as well since they have a knock sensor also.. gives you more options

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Id rather go with option 2. I have to run 4 wires. The motor is complete and comes with a distributor

Do the injectors have different harnesses?

I like the GS-R intake manifold. A huge amount of engineering went into it, and I am impressed by its flat torque curve. This will be a torque motor, not a high HP motor.

Thanks for the tips!

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Bump

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

You can use your half shaft and axles. Injectors and alternator will depend on which engine harness you end up using. If I were you I'd stay obd1, which I know is what your trying to do. Then you can use your alternator and injectors

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Ok so I will do the following:

Swap over injectors
Swap over alternator
Keep my axles
Take my dizzy plugs (2) and rewire for 1, then run the last wire that is leftover to the crank angle sensor

I think thats everything? I'll wire vtec later, I just want to get it running first

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

So your going to use the obd1 ls harness right?

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Yea, and get a rywire subharness for the vtec. I just want to convert the motor to OBD1 basically, with the exception of using an obd2 dizzy (will rewire the plugs)

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Or get a distributor conversion harness.

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

I think I can wire it myself. It's not worth the 30-40$. Plus, I think 1 of my wires from the 2 plugs needs to be re-wired outside the distributor (CFS)

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

You are going to do all that work? All you have to get is an OBD2 harness and its plug and play... most likely will turn out cleaner and its way easier and you can probably find a harness for like 80-100 bucks (IMO worth the money).. then just wire vtec and IAB (I used single runner IM) and knock (I deleted knock via chipped P28) Then it is just two wires in all :beer:

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Or he can do a little extra work and save the money from buying a new harness and he wouldn't have to get new injectors or alternator

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

He wouldn't have to get new injectors or an alternator if his GSR swap came with them... But I guess that's beside the point. Good luck with the swap OP.

Re: Swapping in an OBD2 gsr motor into a OBD1 LS
 

Regardless of what I do, is there anything other than dizzy, alt and injectors that I have to worry about?

Thanks for the help guys!