i'm still trying to get my idle proper on my d15b2, i just changed out the eacv and saw that my old one was dirty as hell...all vaccum lines are perfect, idle ajustment screw has been adjusted back and forth etc etc. i just don't know what else to check right now??? please help.

 

Have you checked the TPS (throttle Position Sensor). I don't know for that particular engine but he ZC should read 0.45-0.5 volts with the throttle fully closed and it may be the same.

 

burned exhaust valves

 

check o2 sensor also :-)