B18B1 OBD2 to OBD1

Hey fellow civicians lol, I posted this in the Integra forum aswell but I think I might get better luck here maybe, anyway..

I have a B18B1 out of a 96 Integra and im 100% sure its OBD2 now but I need to make this engine OBD1. How hard would this be? I know I have to change the distributor and I think I have to change the sensors too?
A distributor out of a 94-95 B18B1 will fit right? Because 94-95 is OBD1? What else do I need to swap?

Thanks for your help in advance!

All you need is the dizzy and to use an OBD-1 ECU/harness.

I'm assuming your car is OBD-1, so use your existing harness. Only hook up the sensors that you have plugs for, don't worry about anything else.

Use the OBD-2 injectors if you can get the plugs for them... you can wire the plugs into your existing wiring harness.. there is no benefit to this other than not having to buy new injectors if you don't already have OBD-0/1 injectors.

Recap: Change the dizzy, possibly injectors, use your existing harness, and OBD-1 ECU. You're good to go from there.

*Edited for being brain dead*

The alternator plugs are different as well. The OBD1 is round and the OBD2 is square (if I remember correctly), but regardless they plugs are different. You can either use an OBD1 alternator, or swap the guts of the OBD1 alternator into the OBD2 alternator's housing. You'll only need to swap the part that the plug is attached to, it will be pretty obvious once you taken them apart.

For the injectors, there is a slight difference other than plugs. I have no idea what issues, if any, that there are with wiring the injectors backwards or not (positive and negative). I compared service manuals before, and the OBD2 injector plugs are wired in reverse from the OBD1 injector plugs. But I've never read about anyone having an issue with wiring them in reverse before, so it might not matter. But personally, I'd just use OBD1 injectors if you have them, for ease of installation.

*edit* This is info for an OBD2 engine into an OBD1 car only, not an OBD2 engine into an OBD0 car: You could just use an OBD2 engine harness if you wanted to use all the OBD2 parts (dizzy, injectors, and alternator), it's completely plug and play with your stock sub-harness.

The alternator plugs are different as well. The OBD1 is round and the OBD2 is square (if I remember correctly), but regardless they plugs are different. You can either use an OBD1 alternator, or swap the guts of the OBD1 alternator into the OBD2 alternator's housing. You'll only need to swap the part that the plug is attached to, it will be pretty obvious once you taken them apart.

Couldn't you just swap the plugs on the harness? Or is there a diff in the amount of pins or something?

For the injectors, there is a slight difference other than plugs. I have no idea what issues, if any, that there are with wiring the injectors backwards or not (positive and negative). I compared service manuals before, and the OBD2 injector plugs are wired in reverse from the OBD1 injector plugs. But I've never read about anyone having an issue with wiring them in reverse before, so it might not matter. But personally, I'd just use OBD1 injectors if you have them, for ease of installation.

You could just use an OBD2 engine harness if you wanted to use all the OBD2 parts (dizzy, injectors, and alternator), it's completely plug and play with your stock sub-harness.

Didn't know that part... about the sub-harness.. then again, how did you? We don't know what car he has, since he never told... although I've seen where diff harnesses have plugged in and been compatible. I can't remember which ones though, I think it was OBD-2 to OBD-1 (B18B in a EG or something similar).

Well i'm doing a swap into my 90 Hatch and also converting it to obd1. And also the B18B1 I bought did not come with a dizzy so I might as well buy a obd1 dist.

Couldn't you just swap the plugs on the harness? Or is there a diff in the amount of pins or something?


And yeah, i'm asking the same question now, couldn't I just use the OBD2 alternator + plug for the obd1 set up?

You could also just use your stock alternator for your D-series...assuming you still have it. All you really need to do is drill out one of the holes on the mounting bracket one size bigger and use the nut/bolt from the D-series alternator.

Its perfectly capable of handling a B-series...because that is what I'm using right now.

But yes you can use the plug and mate it to your harness. Also If the obd2 injectors really are backwards then I suppose im running mine that way. But then again maybe not. I followed the color codes on the pigtails I cut out of the car I got them from (obd2), its really not hard to get the service manuals for all of the cars and just look up the colors.

Couldn't you just swap the plugs on the harness? Or is there a diff in the amount of pins or something?

Didn't know that part... about the sub-harness.. then again, how did you? We don't know what car he has, since he never told... although I've seen where diff harnesses have plugged in and been compatible. I can't remember which ones though, I think it was OBD-2 to OBD-1 (B18B in a EG or something similar).
Crap, I wasn't thinking to clearly. But yeah, the OBD2 engine harness will plug right into an OBD1 sub-harness, and the opposite way (unless it's an OBD2 Civic instead of an OBD2 Integra). I guess this being the 4th gen forum, I should have assumed it was a 4th gen Civic :grinyes:

But yes, the alternator wiring should be the same (from OBD1 & OBD2), both have the same amount of wires, just different style plugs. Even most of the wires are colored the same. But clearly what Tony says to do would be the easiest way of all.

But yes you can use the plug and mate it to your harness. Also If the obd2 injectors really are backwards then I suppose im running mine that way. But then again maybe not. I followed the color codes on the pigtails I cut out of the car I got them from (obd2), its really not hard to get the service manuals for all of the cars and just look up the colors. I could very well be incorrect on this, but either way if it's working it shouldn't be a problem. My brain is freaking mush lately :(

*EDIT* - Ok. I did more think about this and I was wrong...sort of. The negatives and positives aren't reversed after all. But looking at the plugs, the wires are in different positions. If you're looking at the injector wires, towards the firewall, you'll see how the injector wires are. I'm not looking at the wires myself right now, so I'm just going to write out the basic idea of what I'm talking about. Every injector has a Yellow/Black wire, and then a colored wire. The OBD1 and OBD2 injector plugs have the Yellow/Black wires on the opposite sides. So one of the OBD plugs will have the Yellow/Black wire on the right side, while the other OBD plugs will have them on the left side. I suppose I may have been thinking about people who use OBD2 injector plugs and modify them to use OBD1 injectors (pulling out the blue plastic inside). In that case the negatives and positives would be crossed. But I was probably just not thinking :D

he could just did what i did to but an OBD2 engine into an OBD0 car using and OBD1 ecu

So all I have to do is drop in the obd2 engine, swap a dizzy, alternator plug and ecu. Get a conversion harness for my civic from obd0 - obd1 and im golden??

I can even use the obd2 harness or would I need to get an obd1 harness?

You should use your car's stock engine harness and add/subtract/edit where necessary.

It's the easiest way... the thought that you could use the OBD2 harness was CivicSpoon assuming that you had an EG Civic. He's more into that forum :P

Oh btw my car is a DX so i'd have to convert to multi port and then I can cut/splice my stock harness for the B18B1?

Yep. Basically, follow the MPFI swap tutorial, put the harness on your engine, then put the engine in the car, bolt everything in, and plug it all up. Use the OBD-1 conversion harness, plug that up to your OBD-1 ECU, double check everything and start it up.

Obviously, there is going to be a lil more to it than this, but that's the BASIC idea of it. Those are the minimalistic steps.

Hey thanks for all the replies I think I got enough info to keep me motivated for now. I guess I need to read alot more though. Atleast you guys were better help then the Integra forum. That forums DEAD lol.

There aren't too many of us left here that still dedicate any amount of time to posting either.. these cars have just about been covered... I mean, If you look at all the threads in this sub-forum, I'm pretty sure just about every possible scenario is in there somewhere, lacking the ones that are 1 in a million.

Other than that, we just ROCK. You can't get better than this forum. :D

I am eager and willing to help someone who genuinely has an issue that hasnt been covered before. And has taken even 10 mins to search around for the answer. I also like the people who are trying to put newer, better stuff into these cars to keep them alive and kicking.

Best of luck.

Like I said, there are a few of us still.

I'll even help with stupid stuff, but I won't help someone that isn't willing to help themselves... there is some shit that is just so easy, and ppl won't take the 30 mins of staring at the part to figure it out. Those people, I can't stand.

I don't like it when people come on here and expect that we're just going to sit the answers and the work right there in their lap... that's not what we're here for.

We're here to exchange information and goods on a specific level between people who share similar interests... in this case, the interest is in 4th gen Civics, and the tech related to them. We happen to be nice enough to share what we know, but there are conditions to passing on knowledge.

There is no point in wasting your breath (typing skills, etc.) telling someone exactly what to do or how to do it when they can't even take a few mins to find out by using search or google or something... In most cases, searching would have been a faster solution than typing out something like:

"HELP!!! URGENT!!! SOMETHING BROKE AND IT'S MAKING MY CAR WON'T START NO MORE ANYMORE!!! I DON'T KNOW WHAT TO DO NOW WHO CAN HELP ME WITH THIS PARTS IS BROKEN??!?"

Are you serious? Grammar goes a long way.

[/rant]

pithi69, if you need any more help, just ask, we're here.

Thanks, i'm just saving up info and gathering parts but im doing the swap in the summer. I'll try not to be annoying with stupid questions!! haha

I kinda need some help please. I. New to working on cars but I'm trying.. So I bought a b18b1 out of a 2000 integra and put it into my 94 integra LS with the OBD1 wire harness and ecu I think we put the distributor from the OBD1 and the intake manifold and put that on the new motor and at first it had no balls till 3500 RPMs then took off but the warmer it got outside the worse it got. Now when I start my car I can rev it up in neutral and sounds great but once I put it into 1st and press the gas the rpm don't go up or anything what could this be I'm losing my mind I over this. Thanks for any help

kinda need some help please. I. New to working on cars but I'm trying.. So I bought a b18b1 out of a 2000 integra and put it into my 94 integra LS with the OBD1 wire harness and ecu I think we put the distributor from the OBD1 and the intake manifold and put that on the new motor and at first it had no balls till 3500 RPMs then took off but the warmer it got outside the worse it got. Now when I start my car I can rev it up in neutral and sounds great but once I put it into 1st and press the gas the rpm don't go up or anything what could this be I'm losing my mind I over this. Thanks for any help