tysonboy

hi, im gettin ready to do my swap JDM b18c in ek, and i was wonderin do i have to change out my engine harness... since it dont have vtec, i dont want to rewire vtec and butterflies.....but my friend has a 99-00 civic si engine harness layin around...... so my question is would it plug and play on the jdm motors? dont know if usdm and jdm are the same..... and the motor is obd2... and yes i search but really no anwser.... thanks in advance..........

93hondaEG

Yeah its plug and play as long as you use a usdm wire harness from a 99-00 si, but you still have to wire for the vtec unless your car was an ex....

94EG8

You can use a '99 - '00 Si harness if your civic happens to be a '99 - '00. If its a '96 - '98 you will need a '96 - '98 5 speed EX harness, or you will have to modify your original harness.

tysonboy

so i have to use a 96-98 civic ex manual EWH... rite? and it will plug and play into the obd2 jdm motor? will i run into any problems since it is a jdm motor? thanks

94EG8

Yep.

Yes.

The only issue you will have is with the JDM OBD2 vtec solenoid, it will lack a pressure switch that a USDM or any OBD1 ECU will look for. You can either tap the wire for the vtec solenoid into the vtec pressure switch wiring, or use a JDM OBD2 ECU.

B18CivicEJ8

Everything he said and also if you are running a USDM OBD2 ECU, it will look for a crank fluctuation sensor (CKF) Here is how to bypass that:

http://ff-squad.com/wp/?p=309

Oh, and you may have to run 1 wire for your intake air bypass valves. (IAB)

http://technet.ff-squad.com/wiring.obd2a.htm

Vindicator9000

Yes, he will. There's no wiring for gsr butterflies on any Civic harness. It's a round 2 wire connector.... I just cut mine off of a junkyard civic. One wire goes to the ECU. The other.... well, it's a little tricky, and depends on the gsr ECU.

On some GSRs, the power to the IAB is provided by the ECU, so you run the opposite side of the connector to a ground. On other GSRs, the power is provided by a 12V source, and you run the ground side to the ECU. I mean, you just run the positive side of the connector to any 12V power source under the hood, and run the negative side to the ECU. At the correct RPM, the ECU cuts in the ground, activating the circuit, which causes the IABs to open.

That's how mine is, and it's a 2001 engine with an OBD2b ECU. I've heard from several sources that different OBD levels of GSR ECUs are the opposite, so you may have to experiment to get them working, or look up in electrical diagram in the manual.