I have a '74 2.0.
My throttle body has only the vacuum retard opening.
On my dizzy, the vac advance port is blocked with a little rubber thingy. Is this OK, or should I stick a hose on it and leave it hanging?
I can't believe they can through the factory with a hose going to nowhere.
Thanks for your advice and input.

Maybe this will be a better picture.

I meant to type:
"...came through the factory..."
Too much coffee.

I don't have anything on mine, it's just open to the atmoshphere. I'm not sure if having a cap on there would make a difference or not. I don't think it would, but I'm not positive. Pull it off and see if anything changes. Then go with whatever makes the car run best.

You have it right. In 1974, they eliminated the vacuum advance for emissions reasons. They removed the port on the throttle body, but did not eliminate the port on the distributor dashpot. It came from the factory with a hose attached to the dashpot, and the other end left disconnected but tucked down somewhere around the throttle body.

Luckily in CA smog is no longer required for '74 cars. This confuses a lot of smog technicians who also can't believe it came that way from the factory.

You should probably remove the cap as it may affect the operation of the vacuum retard (air may be needed to move through that port in order for the diaphram to move for the vacuum retard). Putting a hose on it will keep the dirt out.

Demick

Demick:
Should I keep it capped?
Or should I stick a hose on it and just let it sit open?
Thanks

I was editing my above post when you asked your question. I'd say get rid of the cap.

That's what Brad Mayeur, the IL 914 guru, has told me. Leave it un-capped.

--DD