Throttle Vacuum on a 3.8L V8?
 

I am still chasing the lumpy idle on my 380SL (Wayward Woman). I recently replaced the injectors, seals, and all the rubber plumbing on the intake manifold. This solved about half of the problem if such things can be quantified.

My question -

The throttle housing has two vacuum lines. One connects to the distributor's vacuum advance via a temperature switch, the other to what looks like an emissions cannister.

I took a vacuum reading off these lines and found I was getting zero vacuum at idle. As I brought the RPM's up, I started registering vacuum about 2000 RPM, and had about 7-10" at 2500 RPM.

Manifold vacuum at hot idle is a wobbly 15-16"

Does this sound right? TIA.