So, my E30 M40 last night stalling in traffic when idle. Then I start up engine again and idle is perfect. Also today, idle is perfect.
Sometimes idle is great for a long time than again, I have problem like last night. Start engine again and everything is normal.
ICV is clean, MAF boot is new, hoses under intake also new. Vacum hoses also. There is no vacum leak.
Is it possible that problem in ECU/Motronic in the term of age ? Which sometimes can make problem with idle ? Also MAF and ICV with purely mechanical problem which occasionally affects on idle.