Rough idle until engine is up to temp - Ambient air temp doesn't matter

[ChristopherL]

Originally Posted by jca

I run the basic Bosch copper core, two prong plugs. Experienced BMW mechanics will tell you these engines run best on the basic plug, which makes fancy plugs a waste of money. If plugs don't fix the problem, I would investigate the idle control valve. It may need replacement or cleaning.

Does the ICV get turned off once the car is at full operating temp?

Thank you,
Chris

[Den]

Originally Posted by ChristopherL

Additional info I should include:

• Fuel in tank is 8+ months old. I've added Dry Gas to try and offset any separation of the fuel as much as possible. . .

I wouldn't bother trying to fix anything until you try fresh gas.

As for plugs, I run the 2-prong NGK's, OE for the M42, not sure about the M44.