Rough Start / Fast Idle

Just got my car back from the mechanic and he says my problem is the vacuum going to the distributor. I'm not getting any fast idle on start up and I have to keep my foot on the gas until the car warms up enough.

Any ideas on what to check other than the lines. I had the black box that controls the three vacuum check valves (or whatever they are called) on the passenger side wall (near the carb) repaired, but I suspect these aren't functioning properly. Are they replaceable ? I don't see them listed in any parts store.

Thanks,

AARON ROCHARD

1976 230.4 W115