This sounds very familiar and I would echo the comments of all those who have advised checking the ECU mapping - in my experience it is important to find someone who is familiar with your specific programme (ie OMEX) rather than a generic tuner and to use someone who does road tuning, not race cars.
The fuelling transition between start/idle and part throttle/light load is notoriously difficult to map because it may under some parameters (temperature, engine load) involve a reduction in fuelling as the throttle opens. If the drop in fuelling values is too sudden you get stalling and then surging if the ECU tries to compensate. If your car was originally tuned for the track this would explain why this part of the map is not finessed.
Good news is on an M engine there shouldn't be a cat and therefore no Lamda input to further complicate the mapping.
Last edited by twotribes; 29/09/14 07:24 PM.
