vacuum chamber?
 

This is either an old issue I should know about, or I am potentially missing something important from my car...

1993 FSM pg C-34 shows a vacuum chamber that bolts between the ignition coils and the solenoid rack. I have no such chamber, and never have had one.

The best I can tell from the grainy online FSM image is that the two lines that should run to the vacuum chamber are, on my car, simply connected with one stretch of hose.

Any info appreciated... sorry if it has been covered before, but my search didn't turn anything up.

Auto only, if you have a 5-spd there is no vacuum tank there.

Thanks much.