I have a 94 vx hatch and im getting a b18c5 swap next week and trying to figure out all this wiring stuff before i get. Im pretty sure ill need an obd adapter for the itr ecu to work,but all this adding 4 o2 wires is confusing me. Could someone send me a diagram or website that shows it exactly and any other wires il have to add?Just trying to get it all layed before I start. If anyone has any pointers before I start my swap please feel free to share. Thanks clay

 

If you search B18C5-EH2's threads, or search on B18C5 your answer will come extremely quick just by reading.

 

Here's a quick reply stolen from myself in an old post:

B18C5 engine wiring into a 1992-1995 Civic:

IMO the USDM ITR swap is easier to swap in. I've done this swap 3 times already and it is 100% easy especially if you run a re-chipped P28 and even more so if you have a 1992 Civic or any 1992-1995 Si, VX, or EX with VTEC wires.

Here's what you'd need too do if you have a USDM ITR swap:

KEEP the ITR engine harness. Regardless of what others say the plugs all plug right in. This way you get to keep the newer ITR distributor and injectors, and there is no need to rewire anything. Again this is from experience, not hearsay.

You'll have a few extra plugs left over on the ITR harness because the ITR has a few extras that our Civics don't have, like ABS, etc. You vcan just hide the extra plugs.

Now there's a few different ways to get an ECU to work, and I'll list them from easiest to hardest:

1. Re-chipped P28. This will simply plug in. No need to wire up for a knock sensor because the P28 doesn't read for one. Better fuel, timing, VTEC x-over, and rev limiter = more power. OBD1 so no need at all to run any sort of extra sensors.

2. Kenji OBD2 jumper harness and JDM P73 ECU. I ran this on my motor for a while before the kenji ECU. You'll have to wire up a knock sensor wire and that's about it. Drawbacks are that this ECU has a 113-115 speed limiter and it doesn't make the power that the kenji-spec P28 does. ThisECU has OBD2 type plugs but IT RUNS AN OBD1 PROGRAM AND IT IS ONLY OBD2 IN PLUGS!!! I ran this ECU with no extra o2 sensor, no crank fluctuation bullshit, etc.

3. Jumper harness with USDM P73 ECU. Why? I wouldn't do this unless I was in Cali and it was necessary for smog bullshit. You'd have to wire up all the extra OBD2 bullshit and the ECU sucks compared to a re-chipped P28.

So that's for the USDM motors, but what about the JDM ITR swaps?

As Apexi-ITR has said the JDM harness can be used. It requires some stretching but it will work. If you must get the factory look then get any OBD2 type engine harness from any USDM B18C1 or B18C5 and then it will plug right in just like I said the USDM swap does.

As far as ECU stuff goes, really a P28 is the better choice again but you will need to add a VTEC oil pressure switch onto the JDM ITR motor because it doesn't have one and the P28 looks for one. Just pull an oil pressure switch from another VTEC motor - didn't you use a SOHC one Apexi-ITR?

Or you can run the jumper harness and O.E JDM P73 ECU. This will save you from having to add the oil pressure switch, but you'll have to add a knock sensor and this ECU still has the shitty speed limiter.

USDM ECU? But why?

That's about all I can think of right now. I run the kenji-spec P28 ECU in my 1992 CX hatchback and with this method and keeping the ITR engine harness I did not have to add one single wire at all! It was absolutely 100% plug and play!

 

*pics by Katman


thought it may help illustrate what Tom was saying....

 

so if i got a rechipped p28 it will plug right in and no wires to add?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clayj &raquo;</TD></TR><TR><TD CLASS="quote">so if i got a rechipped p28 it will plug right in and no wires to add?</TD></TR></TABLE>

PLEASE re-read my reply.

Since your car is already VTEC you will not have to add one single wire at all if you:

1. Keep the ITR B18C5 engine harness and plug it in

2. Run a re0chipped Kenji P28 ECU - kenji211@tampabay.rr.com

Any re-chipped P28 will work, but Kenji's has been proven time and time again to be bad-***. I and many others run his ECU with much success.

 

Would it be the same thing as USDM b18c1 in Eg??How about the ECU issue?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMOKINHATCHBACK &raquo;</TD></TR><TR><TD CLASS="quote">Would it be the same thing as USDM b18c1 in Eg?? </TD></TR></TABLE>

IT is almost the same. GSR motors have secondly butterfly do you will have to wire that up.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMOKINHATCHBACK &raquo;</TD></TR><TR><TD CLASS="quote">How about the ECU issue? </TD></TR></TABLE>

You can use the stock P72 (gsr) ECU. If the motor is a OBD 2, you will have to buy a ECU jumper (OBD 1 --&gt; OBD 2a or b)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbogixxer &raquo;</TD></TR><TR><TD CLASS="quote">
You can use the stock P72 (gsr) ECU. If the motor is a OBD 2, you will have to buy a ECU jumper (OBD 1 --&gt; OBD 2a or b)</TD></TR></TABLE>

No need for a jumper harness. Just buy an OBD1 P72 ECU and plug it in.

If you convert to OBD2 you will hate having to wire p the extra bullshit like the extra o2 sensor, crank fluctuation sensor, etc. Plus OBD2 sucks *** for tuning and they throw more CELs than OBD1 motors do.

My friend's 00 ITR throws so many more CELs than my B18C5 that runs off of a chipped and V-AFC'd P28 OBD1 ECU.

Here's some tasty info on the B18C1 swap into the 1992-1995 Civic stolen from myself from a local ATL MB:

First of all you are not limited to just an OBD1 B18C1.

Why?

Because even though the 1996-2001 Integras are OBD2, their engine harnesses PLUG RIGHT INTO your Civic's underhood chassis harnesses on each strut tower area.

This means you can find a low mileage 01 swap and keep it's newer distributor, injectors, etc.

Here's proof in pics that the OBD2 engine harness plugs right into the 1992-1995 Civic's underhood chassis harnesses.






And don't forget:




From there all you'd need to do is wire up the secondary butterfly **** and the knock sensor as shown here:



Picture courtesy of Jason "Katman" Kaplan.

So about that ECU ****. No need to convert to OBD2 at all. Simply ask the swap source if they can throw in an OBD1 ECU in with the swap and simply plug it right in.

If they don't have one then you will need to locate one and try to sell off yours to a swapper with a 99-00 Civic with a B18C1 in need of an ECU.

1-800-962-8922 is the number to Import Auto Salvage in N.C. They are one of the best swap sources and will throw in an OBD1 ECU with their OBD2 swaps if you ask for it and they have one.