If someone were to take a B18C5 and convert it to OBD1, could they use their civic wiring harness and just add the necessary wires like VTEC, VTEC oil, and knock?

Thanks!

 

Don't really need to convert. Yes.

All the OBD2 stuff is on an extra connector at the passenger shock tower. Just cap it.

 

Ehhh... the distributor on an OBD1 motor has 2 plugs, OBD2 is one plug. Plus, the injectors use different plugs between 1 and 2.

So, if they were to have changed the distrib and injectors over, they could use the OBD1 harness?

 

what kind of civic.. CX? VX?

The B18C5 distributor will have one big plug on it, while your stock Civic and it's engine harness has two plugs. All you have to do is unpin the two lowest fat wires from the C5 distributor and repin them into the extra plug on the civic engine harness.

Here's a picture of the distributor. The arrows are pointing to the wires you need to unpin. This is a picture of an unaltered distributor:



So here's that extra plug on the civic harness with the two wires already ran into it. Notice the wires are the exact same color, making it "idiot proof" so to speak. i'm glad they decided to keep the same colors:



YOu still will have issues

The plug on the C5 alternator won't plug into your harness. There are two ways around this. You could either find an OBD1 B Series distributor, or you can swap the voltage regulator from your civic alternator into the C5 housing. The C5 will have a square plug while the civic harness will have a round plug. Simply pull both alternators apart and swap the voltage regulator. You'll know which part it is because the plug is part of it. A few 8mm and 10mm bolts are all that stand in your way.


Injectors.

The C5 uses OBD2 style injector plugs that will not plug into your civic harness. You can either buy new OBD1 injecotrs for a 1994-1995 Del Sol VTEC or just use your stock Civic injectors.



The easiest thing to do is to use a OBD2 Harness instead of dealing with all that crap and a chipped P-28... and add the VTEC wires. (1996-2001 Integra engine harness. Ideally it should be a GS-R or Type R unit, but if all you can find is an LS then it's only a few extra wires)
Even though the harness is technically "OBD2" it is a direct plug in for the 1992-1995 Civic on the underhood strut tower harnesses.

 

Ah, oops, missed the whole 'civic wiring harness' thing. h:

Personally, I'd pick up a OBD2 harness and do it the easy way.

 

Don't take this the wrong way guys, but I don't think you're understanding my question. This isn't for me at all, it's for some guy that's been emailing me about an OBD1 B18C1 harness that I had for sale on ebay. He was pissed cause he didn't win the auciton and says he as a '95 hatch that he's putting an already OBD1'd C5 motor in. Can he use his stock Civic harness?

 

Um, if the b18c5 has been swapped to OBD1 dizzy and all that kind of stuff... yes? :thinking:

Without modification, maybe.

With modification, definately.

 

I know you can use the stock harness for an OBD1 GSR while running the new wires that are needed. Is the C5 any different? :dunno:

 

No the C5 in this case can be treated the same way. See the problem why you cannot get a real answer is because we do not know what he means by OBD1ed b18c5. Also what kind of a civic? CX? VX?

 

Think about it... all C5s are OBD2. If he changes it all to OBD1 (dizzy, injectors, etc) then the motor is now able to use an OBD1 engine harness. We'll assume it's a DX.

I don't know why this is so confusing. :thinking: