Lumpy Idling after holiday

[Quaser]

Hiya

My mate has an issue with his car - its a 325i and was running fine before he went on holiday - on his return, the battery was flat - recharged it, and the idling is really lumpy now and sometimes cuts out.

Any ideas? its been like this for a week and hes driven it everyday.

Like I said - before the holiday, the engine was as smooth as anything so im stumped!

Q

[Brianmoooore]

Theory: The flat battery caused the ECU to lose idle settings, then the engine movement from the lumpy idle caused the large air pipe between the air meter and the throttle body to split. Idle settings have now sorted, but now have an air leak.

[Quaser]

checked the elbow and that was all fine - any other ideas?

[Brianmoooore]

Do we know what caused the flat battery?

[Quaser]

I presume leaving it standing for around 2 months

[Quaser]

Just spoke to him - it wasn't a flat battery - he disconnected it so it wouldn't go flat