Today swapped the Oxygen sensors with our other M3W. No results. When engine is cold or just warm, idle is like normal. When engine gets hot (after +/- 5 miles) problems with idle starts. Sometimes normal rpm. but most times not. Remains for a short moment around 2000 rpm. after that it drops to 900 rpm. when at standstill. But now the strange things starting. When going downhill and put the car in neutral gear the idle remains all the time around 2000 rpm ! As long you’re driving, even for a few minutes. Slowing down for a stop it drops back to normal idle. Completely weird. If it would be the TPS or the IAC it wouldn’t run normal the first 5 miles as well to my opinion. For sure the manifold valve is moving freely as you hear it closing when depressing the throttle. It’s not the pivot point from the throttle as that’s well lubricated. One more point is that last week we did a 400 miles tour and we had the idea that the M3W with the bad idling used much more fuel as normal but didn’t checked that carefully. It only came to mind when filling up gas. What to check next ??? No I’m sorry I don’t have a computer with Protune and if I would have I’m not sure if I could figure out how to use that computer program. 🥴
