Cant set idle with IACV unplugged without vac leak present.

dr3w · Post by **dr3w** » Sun May 17, 2009 11:34 am

Hi i've had problems with with idle dropping and stalling at lights etc hear and there and finally got fed up. Trying to set my idle higher but with my iacv unplugged it just wont idle.. I just keep unscrewing my idle screw until it popped out and then it would finally idle around 800rpm but the second i slightly put it back in and stop the vac leak it stalls. So i started thinking since this is a Y8 and i ripped off all the evap/etc going to obd1 mabie thats the issue becouse when the evap valve opens etc theres a slight vacuum leak.. So what i was wondering is should i technically have a vacuum leak for proper idle ? i was just gonna put a check valve so i have a slight vac leak/ no boost leak. Any opinions ?

Post by **Bugermass** » Sun May 17, 2009 1:26 pm

you may need to adjust the throttle plate set screw.. You should be able to idle the car at 800 rpm with the air bleed screw in place and the IACV unplugged. If you can't then you need to adjust the throttle stop screw slightly to allow proper air bypass at the throttle plate.

dr3w · Post by **dr3w** » Mon May 18, 2009 5:32 pm

Im gonna throw on another TB on tommarow from a d15b, its got a fitv unlike the y8 one i currently am using. Should i use the fitv since its an obd1 car ? or just keep it unplugged like the Y8 throttle body ?

dbsharp · Post by **dbsharp** » Wed May 20, 2009 5:18 pm

I had the same thing happen on my car. turned out that the Idle air screw port was clogged up pretty good. This may not be your issue, but it wouldn't hurt to check it out.

Post by **Bugermass** » Thu May 21, 2009 12:23 pm

both setting the idle screw and the throttle plate stop screw effectiely create vacume leaks and thats how it allows your car to idle. Same as the IACV.. i would not hassle with the FITV just try cleaning your idle screw port, if that doesn't work then you make need to adjust your throttle plate stop screw.