Kerry:

Either a bad diaphram on the actuator or servo, or a leaking hose (rubber connector) that leaks until you pull some vac on it. Replace the rubber hose and see what happens. If that fixes it, replace all of them, they are all leaking.

You will need to check that the actuator allows enough vac through, too -- connect the Mitivac in place of the servo and see what happens.

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!