I haven't touched the motor, it's a stock 1997 d16y7. It idles fine for a couple minutes then drops, then races and so on. When I drive it doesn't hesitate or surge when in gear. I tried dry gas, then I drove around until the tank was empty, then filled it with 93. I checked all vaccum lines for cracks or leaking, No check engine light. I pulled off the TB and unbolted the IACV from it and cleaned it out, it was siezed in place, (3-wire rotary style) I got it moving again, but the idle still surges. Thanks for the help.

 

check your coolant...make sure there's no air... and any crackings from dried out hoses (vacuum leaks).... does your car have a FITV? if it does then that's the most likely problem.. if not then you probably need a new EACV or there's a bad connection in the EACV line

i would reset the ECU by pulling the fuse just to make sure it updates for current conditions

 

Fixed it! Thought I'd post the solution as well as the problem. It was the IACV after all, I double checked against another d16y7. The good one moves very smoothy and mine felt like there was sand in the "bearing?" anyway it turned back and forth with a lot of resistance. I sprayed it out with carb cleaner and brushed the crap out of it, it's not perfect, but it moves a lot better, and the car idles fine.