i recently did the obd1 conversion to my D15/z6 mini me. when i completed it my car idled at 1500 every time i let it idle after driving. if i let it idle for about a minute it would gradually drop to 1000 or jump between 1000 and 1200. oil change seemed to make it a little better. also the strange part is that there is a whistling/humming noise from my intake. when i unplugged the EACV/IACV the whistling goes away and the idle corrects itself but the ecu throws a code. there are no codes when everything is plugged in. anyone have any similar problems?

 

Reset you're ECU, and adjust the throttle screw to lower the rpms. But that whisling noise could be a leak, perhaps the IACV gasket isn't sealing properly... Definitely check to see if it's leaking first.

 

could be ill pick up some carb cleaner today and check it out. this problem started when i did the obd1 conversion and didnt change when i replaced the iacv so i dont think its a leak. are there any wiring problems that would make the iacv hum or whistle like that. its pretty audible. i can still hear it 20 feet away witht he hood up. ill try adjusting the idle and restsetin the ecu also. the strange thing is it idles at a perfect 700 when i unplug the IACv

 

As said above, your idle is set too high. Idle with the IACV unplugged should be about 500 rpm I do believe.