Does it still do it with the speed sensor disconnected ?
Roger, as your suggestion was the easiest, I started with that this morning.
Surprisingly when disconnected, the idle remained normal whatever I did. Drove for +/- 50 km and put the car many times in neutral when rolling. Idle normal.
I came home and connected the speed sensor again.
I went for a second ride, and now idle also normal. Drove +/- 40 km, switching to neutral many times to see if idle would go to 1000r rpm. All the time normal.
Suddenly the high idle started to show up again. Disconnected the speed sensor plug and directly idle was normal.
The problem must be somewhere in the cable or the plug from the speed sensor.
As I tried yesterday by swapping the speed sensor from our other car, which didn't solve the problem, I don't think it will be the speed sensor itself.
Hope it's not somewhere in the cable to the ECU as that's not an easy job.
So thank you Roger, for helping me to search in the correct direction. We owe you a big beer next year in Grindelwald.
