904 tranny problems

No No No. Improperly adjusted throttle pressure linkage will not cause a car to not move at all. You could take it completely off and the car would still drive forward and backwards, it'd burn up the trans. with it removed or maladjusted but it'd take off.

When my kickdown was reset after reinstall I had the same issue. Too far one way it would slam into gear, too far the other way and it would be mush and require some gas to even move.