OBD-II into a CRX? - Fuel Economy, Hypermiling, EcoModding News and Forum

HydroJim · 08-20-2011, 02:34 PM

Anybody know how I would go about putting a OBD-II engine into a Honda CRX? It seems like it would be hard to convert the car's ECU to an OBD-II ECU.

Reason being is that I really like the shape of the CRX but I really need OBD-II for another aspect of my project.

Arragonis · 08-20-2011, 04:58 PM

Have you decided which engine to use as your swap or is this the question, or part of the questions ?

I don't know what engines are available / used in Civcs in the US but keeping to the same maker may be a simple(r) option to begin with.

HydroJim · 08-20-2011, 05:35 PM

That is somewhat part of the question. I planned on using a Honda engine figuring that it would be easier to integrate but I'm not sure. The other part of the question is that is it even possible to put an OBD 2 engine into a vehicle that was previously OBD0? I know I can buy harnesses that will convert one to the other, but I would like to keep the functionality of OBD 2.

SentraSE-R · 08-20-2011, 07:43 PM

It seems like the way to do it would be to use an OBD-II ECU and an OBD-II engine. The problem(s) would be in getting the ECU all the feedback it expects to see. The CRX isn't going to have airbags, VSS, traction control sensors on the wheels, ABS, etc. A lot of it will come with the engine, but the simpler the OBD-II (1996 v. 2006), the easier your swap will be. The Honda forums will be the place to get your answers.

Old Mechanic · 08-20-2011, 10:30 PM

OBD 2 has things like a sensor that counts the teeth in the flywheel ring gear to determine cylinder power balance or misfire. There are a lot of other OBD2 specific sensor functions that would have to be included in any swap. I am sure it can be done, but it would require some considerable skills by a tech with considerable experience and inventiveness.

Even the post cat second O2 sensor whose purpose is to test the effectiveness of the first sensor and the cat would have to be installed to prevent a CEL.

Basically the pre OBD 2 donor shell would be just that, a shell with everything from the OBD2 donor vehicle fitted to the shell.

regards
Mech

Arragonis · 08-21-2011, 03:19 AM

One other factor in selecting the engine may be the fact that Honda engines used to turn the other way compared to normal engines. Not sure if this is still the case though.

hamsterpower · 08-21-2011, 07:51 AM

Yes, it is possible. Yes, Honda engines used to turn the opposite of most engines, until around 2002 model year, since, they turn the same. The CRX was a very popular shell to accept newer engines and all you need to know can be found on the many Honda engine swap sites. There are kits and harnesses the will help with most any other Honda or Acura engine you can get.

Pick the engine you want based on you project and start from there. Be sure to get every part from the engine, transmission, harness, ECU and sensors. The mounts can be tricky but Most any Honda shell/engine combo has been done so kits for most are available.

An example is someone on here put the Insight drivetrain in a CRX.

Good luck.