stivic

Just did the y8 swap back in my 98 ex. It starts up just fine but has an idle problem. It surges up and down really fast. It has the IAC code 14. I'm using the P2P ECU and I also have an OBD2 P72 I've been trying to see if it runs any better.

I noticed it's a complete y8 swap with obd2 wiring harness but the Intake manifold and injectors are all OBD1 I had to change the injector clips over. Could this be a problem. This is a pic of 1 coolant line coming from the OBD1 intake manifold that I just plugged up because I couldn't find where it went.

slowcivic2k

That goes to the FITV under the throttle body, could also go to the IACV depending on where you put the coolant lines during the swap.

If your TPS is out of adjustment that will cause a really fast idle surge.

Make sure your IACV is plugged in and working correctly, disconnect it with the car running and see if the idle changes, it should maintain around a 450rpm idle without the IACV, if its too much, you have a leak, too little or stalls, clogged PCV.

stivic

ok its not throwing the IAC code anymore its just the oxygen sensor code but that shudn't cause it to idle weird right?

slowcivic2k

No, it should run fine, a bit rich, but fine.

Unplug the IACV one time and see if it idles at 450rpm like it should without it.

stivic

and if it doesn't idle at 450rpm like it should?

slowcivic2k

If it dies, you may have a clogged PCV system, The car should maintain an idle of 450rpm with no input to the IACV, if your PCV is clean, adjust the base idle by turning the adjustment screw until you reach 450rpm.

Make sure your IAC is wired to the ECU correctly. A quick test to determine if the solenoid is functional is to remove it from the manifold, and hook a spare connector to it, and run one to the battery positive, and another to the negative or a good ground, the solenoid should "click". Do this only briefly to determine if the solenoid actually works.

stivic

Yeah I already ran it to the battery it did click