I have a similar problem that I have not been able to figure out. I have an obd2 vr from a '97 Jetta with A/C delete. When I start the car cold first thing in the morning, I get a bit of a high idle. It stabilizes after warm up; driving half a block or letting idle for a couple minutes until it drops on its own. Then once the engine reaches temperature, the idle will increase to 950rpms from 680rpms. It stays at 980rpms until you restart the engine then drops to 680rpms again. The rpm increase seems to happen when the fans kick in. I've changed the FCM, O2 sensor, MAF, plugs, plug wires and temps sensors. My second speed radiator fans was not working so I did a bypass harness. Also, my 4th speed cabin air fan does not work. It also has an unknown but new throttle body that seems to sync fine according to VAGCOM. The engine performs great otherwise and has passed BC's aircare in early 2014. I suspect the following:
1) something to do with A/C components being removed
2) unknown throttle body, probably Chinese made
3) something emissions that opens up a vacuum leak when the car is warm
Let me know your thoughts.
