Vacuum Advance Connection

V

vin-kohler

Member
2000TC with HS8-carbies.

As I understand things the downstream side of the carbies should be connected to the vacuum advance. In my case the rear carby has its nipple at the bottom, the front carby on top. WHY?
Currently only the rear is connected to the vacuum advance, the front nipple is plugged closed. Is that the way to do it?

Vin
 
I couldn't remember, so looked in the WM, and that shows the tube fitted to the top fitting on the front carb, and no mention of another fitting on the underside of the rear carb in the illustration as far as I could see. I don't remember having to fish around under the rear carb to remove/refit the vac pipe. All I could think is that the extra vac point would be for something emission related.

All or any of the above could well be challenged later....
 
Hi Vern. Can't send a picture just now as everything has been assembled. But I anticipate further fiddlings. Will make a picture then.

Vin
 
I've just had a look at a spare set of HS8s and they only have the one port on top. I'm with Harvey, some export/emission setups had a vacuum advance and retard arrangement but if your distributor only has the advance connection, then just plug the pipe under the carb.
 
Hi Vin, hopefully the pic below will help you with the vacuum ports.

Best,

Steven
 

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  • carb-ports (791x613).jpg
    carb-ports (791x613).jpg
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Vin, I checked out my carbs today. The rear carb does have a connection between the carb and the filter. It's hose goes to the breather on top of the valve cover. Hope this helps.

Steven
 
Thanks KiwiRover, thanks Steven.

With the underside port - which is the one currently connected to the dizzy - I tried to measure the vacuum. I've let a tranparent tube hang into a water container so as to measure the water column. But I gave up after 1 meter. The length of the tube did not permit more.

The rear carb does have a connection between the carb and the filter. It's hose goes to the breather on top of the valve cover.
Click to expand...
That had been done.

But there is another puzzle. From the inlet manifold there is a rubber pipe running to an assembly consisting of a solenoid with a plunger. With the solenoid energized the plunger opens a port so as to let outside air enter the manifold. As the power lead to the solenoid had been ripped off it has never been activated since I have the car. I resoldered the lead which was dangling around.

Now: What good does that assembly do once connected?





And once again I don't know how to attach pictures.
Vin
 
vin-kohler said:
But there is another puzzle. From the inlet manifold there is a rubber pipe running to an assembly consisting of a solenoid with a plunger. With the solenoid energized the plunger opens a port so as to let outside air enter the manifold. As the power lead to the solenoid had been ripped off it has never been activated since I have the car. I resoldered the lead which was dangling around.
Click to expand...

Some cars had a valve that dumped air into the manifold when switching off, and others had a plunger that slowed the rate that the throttle closed when lifting off the throttle pedal for emission control purposes. What you've pictured looks like a dump valve and a lot of those were fitted to cure running-on.
 
Thanks Harvey. So I'll leave the electrics unconnected.

And as an aside: When I scrapped my previous P6 more than 30 years ago, I installed said solenoid as a code controlled opener for my frontdoor. It is still operational.

Vin
 
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