Couldn't be the vac modulator, that only runs the "feel" (engagement speed of the shift, not timing).

Could be a loose or broken bowden cable, or a shorted or stuck kickdown switch (under the accelerator pedal).

However, this particular shifting behavior is often a valve body problem, requires serious work. Check the ease stuff first....

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!