When I turn on my car and it's not warmed up, my idle #1. is really high and #2. becomes erratic going between 1000 and 1500 rpm. After it's warmed up, it idles at 750 rpm like a champ, solid. I am using Uberdata, with cold idle set at 1000 rpm, running idle at 900 rpm, and standard idle at 750 rpm. Engine speed is now going as high as 2000 rpm when I first start the car. My ecu has closed loop mode disabled. I suspect my problem might be a vacuum leak. Any other ideas?

 

mine does the same thing cold...if it was a vac leak it would do it cold or warm.

 

thats because your FITV is letting air in when the engine is cold. set your cold idle to 2k and I bet it'll be smooth as silk.

 

It's possible and worth a shot, but from what I've learned the ecu really has minimal control over how the engine is going to idle.

 

the FITV is designed to let enough air in for the engine to idle at 2k for cold start. If your ecu at the same time is targetting 1k it'll will fall down and then jump back up. thats my view of the hole problem. hell It can't hurt to burn a chip and plug it in and try, right?