Bare minimum for engine swap

**CptKaos** · 25-09-2014 05:28 PM

Hi all,

I want to use the driveline, ecu, fuelling etc out of a ITR DC2R for a kit car I'm building.

Now I want to keep the car wiring, lights, horn, brake lights, indicators etc separate from the ecu as much as possible, so my question is, what ecu do the DC2R's come with, and what are the bare essentials needed to run the motor?
Also I'd like to run and aftermarket dash such as the Haltech, Digidash or Aim dash, so is it possible to run these sensors (oil p, temp, tach, speedo) straight from sensors to dash, or does the honda ecu need the inputs.

My problem is to get registration I must run the stock ecu, intake, exhaust, fuel pumps and all emissions sundries, but I'm sure alot of these will "fall off" after rego, so I need to find out exactly what the ecu needs to run.

Am I correct in thinking the original DC2R ITR ecu is not compatible with Hondata piggybacks?
Are there any aftermarket ecu's that will handle the B18C7 as well as the honda ecu?

The car will just be my blat toy, and will be tracked 10-12 times a year as well, and will take the place of a westfield clubman I currently have.

So yea, atm I just need to know what are the bare essentials I need to run the motor, any advice is greatly appreciated!

TIA
Alex

**mocchi** · 25-09-2014 06:01 PM

you talking about sensors? can only think of fuel vapor purge solenoid. i think the rest of sensors will throw cel if removed and engine wont run well.

**dorikin** · 25-09-2014 06:17 PM

What I would do is use the complete DC2R engine harness + the section of the chassis harness that runs to the ECU (you will have to slice this out).
This will basically connect Engine > ECU

From there you will have to wire in (at minimum) the following to the ECU from your kit car:
-Voltage Backup
-Brake Switch
-Fuel Pump Main relay
-Starter Switch signal

From the driver side of the engine harness:
-you will need to supply 12v ign power to injectors, o2, iacv, vss, alternator
-these sensors go directly to cluster, RPM, Coolant temp, Oil pressure switch

You'll also need to wire in the Fan Switch directly and disable the ECU immobiliser if you're using an AUDM P73

**ECU-MAN** · 25-09-2014 06:46 PM

Once you have it running with the stock OBDIIa ECU you can then use a conversion harness and an OBDI ECU that supports Hondata etc to make it tunable.

**CptKaos** · 25-09-2014 07:01 PM

Excellent info thank you all.

So I'll need all engine sensors and solenoids except fuel vapor purge solenoid?
When you say "the section of the chassis harness that runs to the ECU" I gather that is Battery pos and neg, ign feed plus the other 4 you mentioned, Voltage Backup, Brake Switch, Fuel Pump Main relay, Starter Switch signal?

Does the conversion harness and an OBDI ECU replace the OEM ecu or work alongside?

Thanks again for your time, I appreciate it.

**mocchi** · 25-09-2014 07:12 PM

Originally Posted by CptKaos

Excellent info thank you all.

So I'll need all engine sensors and solenoids except fuel vapor purge solenoid?
When you say "the section of the chassis harness that runs to the ECU" I gather that is Battery pos and neg, ign feed plus the other 4 you mentioned, Voltage Backup, Brake Switch, Fuel Pump Main relay, Starter Switch signal?

Does the conversion harness and an OBDI ECU replace the OEM ecu or work alongside?

Thanks again for your time, I appreciate it.

hondata only runs on obd1 ecu thats why you need the conv harness. the hondata + obd1 ecu replaces your itr obd2 ecu
the purge solenoid might be needed for emission testing though, im not clear on that
i suppose you can just plumb charcoal canister without the solenoid like how honda did it in early model integras.

**CptKaos** · 25-09-2014 07:16 PM

Ok cheers, that's clear now.
And the whole point of using all the oem gear is so I don't have to do an emissions test, as long as I use everything out of an Aus complied car the engineer can just sign off on that side of the build without a test.
It really just has to "look" right if you get my drift.

**dorikin** · 25-09-2014 07:25 PM

It will make more sense when you strip the donor car but basically the engine harness does not run directly to the ecu. it plugs into the chassis harness near the strut towers

So essentially you will need to customise your own engine harness

**CptKaos** · 25-09-2014 07:35 PM

Which is pretty much what I will do anyway, trying to put an entire OEM harness into a custom build always looks like a dogs brekky, hence my need to know the bare essentials to run the motor.
I just replaced the OEM 4AGE ecu in my clubbie with a Haltech unit and yeah, it was easier just to gut the whole lot and start from scratch.
As you say it should be easier once I have it laid out in front of me, just trying to get my head around it first, Honda and Toyota seem to do things quite differently re wiring...

Do you know if the wire colors carry through the same from the engine harness, to the chassis harness and onto the ecu plugs?

**ECU-MAN** · 26-09-2014 07:50 AM

You need to get yourself the PGMFI schematic for the Engine and study it. You can then take what you been from the cabin harness and make your own harness u p from that.