What is wrong with my idle? Idling at 2000

[bigstick]

So my s14 has been idling very weird for the past few weeks. Basically when I start my car and start driving, it idles fine for about 3-4 minutes. After 5 minutes and once it's warmed up it'll start idling at 2k. After about 30 minutes of driving, it'll finally start idling fine. Anyone know what's causing this? Basically when I'm stopping at a stop light and I throw it in neutral, the RPM will start rising until it hits 2k and stay there, and then once I pull the e brake up, then it'll drop to around 1k. Do you think a vacuum leak is causing this? Or is it the IACV? Thanks!

[besTint]

could be either of those but i would lean more towards the ecu temp sensor. cheap, easy fix and you can get it at the nissan dealer.

[Mishkin_707]

What he said^ disconnect your coolant temp sensor, red two pin connector, start the car and drive it if it doesn't act up then BAM! should be like $26 at your local parts store, but test it like I said to before you buy the sensor.

[bigstick]

Thank you guys so much! I'll try this tomorrow

[bigstick]

Quick question, how do I remove it?

[Kingtal0n]

Engine idle is affected by airflow. The more air entering the engine, the higher the idle will be. Keep this in mind as you diagnose this problem, you are trying to find a place where too much air is entering the engine. It could be a bent throttle shaft, a vacuum leak on the intake manifold, a stuck open IACV valve, an improperly adjusted IACV/Throttle body, a dirty IACV, etc...

It does sound like an IACV issue, since you say it idles fine sometimes. You can try removing it and cleaning it, but I would just replace it with a known good unit. Or you could try unplugging it also to help diagnose the issue.
the coolant temp sensor is also a good idea. If the ECU "can see" a low temperature it may raise the idle unnecessarily.

[besTint]

Quick question, how do I remove it?


remove the plug and it should be like a 12mm socket. i will double check the size.

[bigstick]

Yeah I think its an IACV issue, basically when I'm coasting in neutral the idle will go to 2k, but then once i stop and i'm stationary, then it will lower to 1k, but as long as im rolling it idle up to 2k, I'll try cleaning my IACV and see what happens, thanks for the help guys

[besTint]

if your gonna take out the iacv to clean it, the best thing to use is CLR. works better than carb choke cleaner or brake cleaner. just fill the coolant lines with it and let it soak, it'll break apart all the corrosion in there and you can flush it out with water.