Gregor, has the amal valve been discarded and replaced by the bleedvalve or are they operating along side each other.

If the amal valve is in any way attached, try and disconnect the wires. If the boost drops a bit but remains steady then your amal valve or electrical connection to your amal valve is faulty.

In the other case, test the wastegate by hand. You shouldn't feel ANY resistance at all.

Where did you go for a setup here in the Netherlands and how much does this cost?