Running lean summer and rich winter with supercharger ?!?!

Exactly a year a ago I have installed an AA supercharger on my BMW 330ci.
This BMW is my daily driver and also my lapping car. It runs greate except ....

So I installed the SC back in January 2008. I bought it in Miami while I was on holiday. Installation went perfectly and from minute 1 car was running 10/10 until march ... when the temperature got above -5C.


When I start the engine, until it gets fully hot it runs lean (20AFR ! :run: )between 1500rpm and 2000rpm when the temperature is above -5C ... Strange isn't .... Once the engin is hot the lean condition disappears and engine races 10/10. This problem is painfull when I go to work in the morning. During lapping you will not notice it since the engin is always red hot.

Below -5C engin runs perfectly even cold. :dunno: Don't ask me why ...

When AA has done the programming I have requested a couple of extra settings. I have the impression that they have screwed up something in the open loop operation while the engin is heating up.

Any body had similar issue in Canada ?

It only runs lean when cold on startup or it does it while driving too? What's is your airfuel gauge? The 02 sensor won't give a proper reading until the element is warmed up. Any issues other than the lean reading on the gauge (bucking, misfiring,etc...)

The problem only occurs while the engin is cold and the next 4-6 min until the engin is fully hot. I am using an innovate WBO it is very accurate and symthomes collerate to values read from the AFR tool.

andkovacs said:

The problem only occurs while the engin is cold and the next 4-6 min until the engin is fully hot. I am using an innovate WBO it is very accurate and symthomes collerate to values read from the AFR tool.

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It has done it ever since the software has been installed? Or started doing it later on? In other word could a coolant sensor, air intake temperature be the culprit? If it's from day one I would contact your nearest Active Autowerk authorised dealer to see if a software revision could be done as far as temperature correction maps wich might be a little off.