s14 sr20kouki annoying idle issue

[s14slowjuice]

And yes i have searched a whole bunch. Cold or warm my idle will sit at 1100 - 1300 rpms then it will dip down to normal range at 750 for a bit and stay. Sometimes it wont and go right back to 1100ish rpm. Then while driving if i come to a light and throw it in neutral it will drop to 1500 range and slow work down to 1100 after a minute again it will go to normal. then shoot back up. It fluctuates like this regularly. I just changed my spark plugs and now it doesnt sound like it is a bout to die when it hits 750. In searching people say its most likely a vacuum leak or that the iavc needs to be cleaned, what the hell is the iavc???? i have searched and cant figure it out. I kinda have a idea on where it is at or around. so if someone could explain that it would be appreciated, Anyone input or advice is helpful. Thanks. Again i did search but have no idea on how to do what some of the people described.

[2.5T_/<ouki]

I've had this problem before. It turned out it was my TPS. It was getting so bad that the RPM's would be so high that i really didn't even need to press the gas pedal, it was like driving an automatic car.

I would check your IACV (Idle Air Control Valve) it sounds like it is hunting for an idle. You can always clean it out and make sure that everything is still functioning.

Also, check for boost leaks by pressurizing your setup. Using soapy water to detect air is probably the easiest way to spot a leak.

Another thing you may want to check is your coolant temp sensor. This can cause an effect just like you are experiencing.

[s14slowjuice]

Hey good looking on the input.Hopefully it will be warm enough tomarrow that i can get out try some of these ideas

[rb20240sx]

Check tps voltage make sure the middle white wire is at .5 volts closed. Then adjust iacv accordingly might want to also clean the iacv with some brake cleaner they like to get gunk in them, also clean throttle body plate. Should idle amazing after all that.