I will swap the amal valve tonight with the one from Marco's car. If that doesn't help I'll try what Tony suggested.

My brother didn't bought the chip from Gerry, it was allready in the car when he bought it a couple years ago. But the car was rarely used so he never noticed this issue really. We are from Limburg so that should be to far of you I guess

I'll post an update as soon as I know more.