I noticed that the vacuum line to my car's distributor retard unit is AWOL. Two questions:

1. Is there any reason I would not re-attach this?
2. Where does it normally attach?

Tom

 

Unless it's got one of those super duper electronic ignition including electronic timing devices, then it should be connected.
First plug the pipe into the vacuum advance unit on the distributor and suck on the other end. it should hold pressure or the diaphram is punctured. If you then switch the engine on and use a timing light and suck on the end again (be Careful of the big spinny fan thing on the end on your engine!!!!) the timing marks should move. With the pipe disconnected you can set the static timing.

Then switch the engine off and find the hole where the other end of the pipe fits........ Haven't got the car in front of me but it should be fairly obvious, might have had a hissing sound when the engine was running.

 

Thanks, anjum. I am comfortable with how the system is supposed to work, but I have no idea where it should attach to the manifold.

If anyone has a picture of the engine bay showing precisely where the vacuum tap for the dizzy and the temperature sender are located, I would be quite happy!

 

From memory One end goes onto the distributor and the other attaches to the valve body at the air cleaner. I'll check my vehicle over the next few days.

 

Well, I got my hands on a copy of the Workshop Manual, but it seems to be geared to home-market cars with SUs fitted (wouldn't that be nice?). There are remarkably few diagrams, and none of the intake that I could find, nor is there a vacuum diagram.

However, it does seem that the vacuum connections are supposed to be on the underside of the intake, and perhaps at the rear. I am now 3,000 miles away from the car, so I won't be poking around under the hood anytime soon!

I did find one interesting piece of information:

"The fuel line filter is located in the luggage compartment when the air-conditioning system is fitted. Accessibility is gained after removing the spare wheel."

This describes my car, and combined with the "Cold" knob by the radio, I think that the car might have come with A/C originally...that would prove interesting!

 

Also, does anyone have photos of a NADA-spec intake manifold top/bottom so I know what I am looking for?

 

I have now checked my vehicle (UK spec 1976 4.2 litre with twin S.U. carbs) There is a flap valve fitted into the air pick up pipe. This has a small diameter rubber tube running back towards the air cleaner box. It fits onto a metal tube fixed to the engine side of the air cleaner. Right next to this connection is another metal tube - this is where the distributor vacuum advance tube fits. All are push fits. Hope this helps.

 

Thanks for looking, but I am fairly certain that the US-specification distributor is different than the home-market cars. After some digging, it seems that the home-market cars would have a vacuum-advance distributor connected to ported vacuum on the SU carb. The US-specification cars came with Z-S carbs and a vacuum-retard distributor connected to manifold vacuum.

So, the answer to my question is that the dizzy should attach to the underside of the intake manifold. That's what I have come up with, anyway. Anyone who knows better, please correct me!

Tom