Ok, I got a 1990 CRX Si, with a S1 B16a1 in it, and I am getting a really high idle when the IAC is plugged in and a up and down idle like 1g to 2g idle when its not plugged in.. I put a straight 12v connection and ground to the IAC to see if the sensor is messed but it clicks fine, and then I tested to see if there was voltage comming from the harness and it has battery voltage.. So I have no idea what the problem could be.. if anyone has any ideas it would really help me out...

Thanx.. Pete

 

i'm actually interested in knowing b/c i have the same problem with my IAC valve. i've posted several times on other boards and they didn't know what it was. i have a jdm b16b ctr motor with a ctr ecu. during my swap, i used my 2000dx harness. the iac valve works. like QWKPHKR, i plugged it directly to the battery and it turned on. the problem is finding the right pin location for me. here are the ones that i've tried: A12, A13, A14, B2 and B23. i have a 2000civic si helms and those were all the locations for obd2 ecus. none of them worked. there was NO power coming out of any of them. does anyone have the ECU pin locations for jdm b16b (PCT) Civic type R ECU??

 

If your IACV is unplugged your car shouldn't idle at all. It should die. You won't be getting any airflow, so it will stall. That's what happens when I unplug mine. Having a high idle is related to a vacuum leak. Try this: Get one of those cheap $5 spray bottles and mist water into your engine compartment around your IM. If you see it getting sucked in, then you know where the leak is.