B18cRuNNer

ok lately ive been running into problems with the b18c1 in my 95 si eG, the motor is a obd-2 harness connected to a obd1, is there any other wires that should be ran besides the ones connected, the car's iac sensors doesnt work so should i switch my obd-2 harness for a obd-1... please help me out guys the car dies and bogs

YumVTEC

do a search please. you will have to add IAB and knock wiring to your Civic intermediate (goes through firewall) harness. you may have to switch two of the IACV wires, but I'm not sure.

poison

is the car still obd1?

I would convert the motor to obd1 and use an EX/Si harness and wire it up that way.

VTECVillain

I assume you are using an OBDI ECU then a complete OBDII motor and harness? Having an OBDII Integra harness in the OBDI chassis doesn't make a difference but adding the extra necessary wires does. You will only need to wire up the Knock sensor and IAB since you have a Si which already has the VTEC pressure switch + solenoid and the 4 wire O2.
I have a 99 B18C1 in my 92 VX and there were no issues by using the OBDII harness. I did the swap myself and I've had it in for about 3 years now. Don't go back to OBDI parts because it's simply a waste of $ and useless to do that.
You say that the problem with the IAC occurred "lately" so again I'll assume that you've drove it for a wile and it has ran fine up until recently. It's sounds like you've pinpointed the problem so why not investigate the wiring for that sensor and troubleshoot rather than replace all OBDII components and harness to OBDI?

JDMCivicEF9

I'm doing the a 99 ITR swap into a 94 Civic EX. I'm kind confuse about the wiring part. Can I still use my EX harness for the swap or do I use a OBD2 harness and get an OBD2 to OBD1 conversion. Then run it with a chipped P28 ecu?

YumVTEC

it depends if your swap is USDM or JDM. If it's USDM then the harness on the ITR motor will plug right into the shock tower plugs of your Civic intermediate harness. since your car is an EX, it is already wired for VTEC, so yes, all you'd have to do is plug in a chipped P28. You could run an obd1 p30 too, but that's up to you... (i think that might need knock wired up).

boostindoo

I have an OBD 1 Civic. Does it make a swap much harder to do by choosing an engine that is obd2? For example, putting a 1999 B18C1 into my 95 Civic EX coupe? I know of the wire harnesses that can be gotten for this kind of swap but i read on a site that it is not recommended?? What are your thoughts on this?

Answer:

If you get the wiring harness with the '99 GS-R swap all you need to do is drop it in, plug the engine harness in, and add wires for the VTEC solenoid, knock sensor, and VTEC pressure switch.

Get an OBD1 GS-R ECU. It plugs right in.

For the IAB you will need to move A20 to A17. Since you will be using the OBD2 engine harness and an OBD1 GS-R ECU you will need to cut the black wire at the IAB plug and give it a 12V switched source. You can get this from the yel/blk wire at the injectors or the IACV.

The reason this needs to be done is due to the fact that the OBD1 GS-R ECU uses a negative trigger to activate the IAB and the OBD2 GS-R ECU uses a positive trigger to activate the IAB. If you use the OBD2 GS-R engine harness with the OBD1 GS-R ECU the IAB will not work by just moving A20 to A17 (as with an OBD1 GS-R ECU and OBD1 GS-R engine harness).