I have a project EG hatch and just picked up a parts car which is an EK coupe. The EK has a B20 Vtec that I'm swapping over to my EG, it also has a Rywire Harness. I'm running a Hondata S300 in my EG and I'm wondering if I could take the wiring harness from the EK and use it in the EG. Can't find answers on this. The wiring in my EG currently was butchered by the previous owner, I'd love to get it replaced with something cleaner.

 

It would depend on if the engine harnesses are OBD1 or OBD2. There are differences on the alternator and distributor plugs between OBD1 and 2, and I think some other changes as well. If they were running a B20VTEC, I would assume that they had an OBD1 ECU that was capable of tuning but they still could have been using an OBD2 harness and an OBD2 -> OBD1 conversion jumper.

I would anticipate very little to none of the dashboard or other interior wiring/harnesses to be interchangeable.

Note that the Rywire harness will be missing a plug for VTEC oil pressure sensor, knock sensor, and air conditioning. For the most part, possibly with some minor changes, the engine harnesses should be interchangeable. We'd need more info and someone smarter than me will have to respond beyond that.

 

Thank you for your response! I'll go ahead and attempt to use the harness in the EK on my EG.

If the motor was OBD2, would it be as easy as finding the proper conversions to OBD1? Are those plugs you mentioned that Rywire leaves out particularly important?

 

No you cannot use ek engine wiring in an eg.

 

Neither knock sensor or VTEC pressure sensor are needed if you're running a chipped or aftermarket ECU. Knock sensor may not matter either way, but you'll need the VTEC pressure sensor plugged in for VTEC to engage unless you've accounted for that in tuning, and bypassed it (any ECU with a chip or standalone can do this). If you need to add wires for the VTEC pressure plug to the Rywire harness it shouldn't be too hard, it's only two wires you'd need to run and then plug in.

You should find out first what parts of your B20VTEC engine, and your harnesses are OBD1 and OBD2. What ECU do you have? What you'll need to do will depend on what your engine/harness/ECU combo is, in any case with the parts you have you should be able to make something work relatively easy.

I know that OBD1 engines will have two harnesses plugged into the distributor, whereas OBD2 distributors will only have one harness to plug in. I'm going to stop from saying more now, because I've only ever dealt with straight OBD1 configurations or full standalone systems, I have 0 hands on experience with OBD2.

This site may have some helpful info, scroll down where it talks about ECU and Sensors:
https://technet.ff-squad.com/index.htm

 

I just emailed Rywire, they seem confident that I can use the EK harness. I'll report back how it works out for me when I start swapping.