Like the topic says i have a really retarded idle problem with my d16y8. The car was supercharged for a few months and after i put my stock intake manifold back on it started idle-ing pulsing between 15-1700 RPMs. The car would start up fine but as soon as it gets warm it starts pulsing, every once in a while it would stop pulsing and then idle at 1500 RPMs. any idea on whats wrong? i buddy of mine told me it could possibly be the intake manifold gasket and throttle body gasket, but i wanna get an idea of what else i should look at before i start taking stuff apart. BTW, IACV is fine. thanks my dudes!

 

codes? if not.. check for leaks.... intake manifold, tb etc.. also burp your coolant.. air bubles in the coolant can cause idle iregularities.. i know you said iac was fine but couldnt hurt to pop it off and make sure its clean.. if you have an fitv.. which i think you do... might wanna do a search on how to fix them.. there are plenty of threads about fitv maintenence

 

so i think i found the problem. where the intake manifold meets the block theres a opening for a hose to connect to that wasnt connected, its directly in the middle of the intake manifold where it meets the block, anyone know what it is and what hose connects to it? im pretty sure its air or vaccum, not a coolant hose. as soon as i put my finger over it the RPMs drop all the way down to like 800 rpms and stops pulsing. btw, the motor is a 99-00 not 96-98 d16y8(difference in the intake manifold)

 

Just go to a parts store and get a vacuum cap.

 

first i would make sure that there isnt a hose that suppoesd to be going to that stem.. if its in the front and its a large stem its most likely for your evap canister. if its a thin stem its probably for your fpr but i think youd be having more problems with ur car if it was..

 

thanks for the help guys! everything seems to be working fine now. i just went and did emissions and i failed because of the air intake temp sensor and the idle air control valve. Im gonna take apart the iacv and clean it to see if thatmakes a difference and then im gonna steal my brothers air intake temp sensor, should solve my problems.

 

if it is the small nipple pointing straight up in between runners 2 and 3, it is for the air injection which was only on 99-00 EX's. you can either hook it up according to the manual, or plug it off, it shouldn't make any difference.

 

ok i know it might b wired but try and changing ecus

my stock y8 had the same problem and i even check all lines, leaks and so for had code 14 that went away after changing ecu
its a shot to check it

 

that happens when your wires are crossed and a you send a 12 volt charge through the wire into a place that isnt' suppoesd to have a charge that high .. as a result you burn out the driver in the ecu and in turn need a new one