Problem fixed, but I don't know exactly how
Since I urgently needed the car I switched the pump for the 1Y one, and it was OK. A little down on power and no smoke.
Than after the weekend I took most of the AAZ pump apart and nothing seemed to be wrong. So I put it back and it still didn't have power, but it also didn't want to smoke (even on the spot).
Played with the max fuel screw - a bit better.
Replaced the filter - a bit better.
Checked internal pressure (was low) and adjusted it to spec. - a bit better.
Adjusted the throttle limiter plate - a bit better
Then played with the max fuel screw again and it took off like it should.
I guess it was a bit of everything.
Now I modified the stock AAZ boost pin and made a boost controller (set to 15psi) and the vanagon flyes
Next stop is figuring out how to mount a intercooler.