A 00 1.9td transporter does not have an air mass meter, it is most likely a small shock asborber on the diesel pump that damps the movement of the throttle, simply remove it and dont replace it because it does not need it.
Failing this the throttle cables tend to seize and collapse as you press the throttle, you can see this with the help of a second person pressing the throttle and looking at the cable near the bulkhead, if the small shock absorber on the pump is stiff, it will cause the cable to collapse as well.