Distributor

[bowserdog1]

I have an '82 US 928. I just noticed that I am missing the vacuum retard line for the distributor. I know where it connects on the distributor but where does it connect to on the other end? Can someone post a pic for me?
Thanks.

[MPDano]

Originally Posted by bowserdog1

I have an '82 US 928. I just noticed that I am missing the vacuum retard line for the distributor. I know where it connects on the distributor but where does it connect to on the other end? Can someone post a pic for me?
Thanks.

All the Vac lines should go back to the throttle body area. There is a vac diagram posted here somewhere.

[bowserdog1]

I see a vacuum line just to the right of the idle adjust screw on the throttle body that is capped off. Is this the connection for the retard line on the distributor? Is there any reason to cap this off and not connect to the distributor?

[Danglerb]

Throttle area has 4 kinds of connections;

Constant manifold pressure, after the throttle plate far enough to always have same pressure the cylinders actually see. Fuel pressure regulators use this, maybe dist too.

Manifold pressure off idle, ambient at idle, barely below the throttle plate, plate goes below it off idle. Maybe dist, used to control other valves.

Manifold pressure at idle, ambient off idle, barely above the throttle plate (other side from above), plate goes above it off idle. Mostly used to control other valves.

Constant ambient, below the throttle plate far enough to never see manifold pressure except at maybe full throttle and high rpm, then its still ambient less pressure drop of air filter etc. Breather lines for air that has already gone through the air meter.

The 928 had different types of distributor over the years, some are vacuum advance, some are vacuum retard, or something like that, some maybe both. You need to find the vacuum diagram for YOUR car and fix all the stuff that is routed wrong.