Distributor, not recieving Vaccum Suction

[JMcTurnan]

So my carburetor is not working right, it is not recieving suction through the small tube hooked to it for the distributor, any ideas?

[fordman]

it sounds like you are talking about it backwards. the carb sucks the dist advance. the advance doesnt suck from the carb. but thats probably not what you meant. the dist vacuum is suppose to fit on the bottom of the carb on the passenger side. it sould suck from one of those ports. if its not sucking try the front or rear port to get vacuum to work the dist. if you have vacuum but the advance isnt working then the advance might be bad and could need to be replaced.

[Hawkrod]

Also note that you won't see any vaccum signal with the engine sitting there idling, it only gets vacuum when there is a load on the engine which means the throttle plates are open and not just cruising along. Hawkrod

[cdherman]

Also note that you won't see any vaccum signal with the engine sitting there idling, it only gets vacuum when there is a load on the engine which means the throttle plates are open and not just cruising along. Hawkrod

Depends on the carb that he has. Several of my old Carter YF 1 bbl carbs have ports for both ported vacumn (above the throttle plate) and straight manifold vacumn. With those you can choose your vacuum source. Partial throttle with no load will also produce some vacumn on a ported vacumn, as the vacumn port above the throttle is just above the throttle plate -- meaning that even cracking the throttle plate exposes the port to some vacuumn. (And then there's the discussion of venturi effect which we can perhaps agree to leave out...)

In any case, a vacumn guage and length of hose passed into the cab can be real handy in figuring out just how your vacumn behaves under load versus at partial load and no load.....

[FORDification]

Also....were you all aware that at least on the '67 V8s with an automatic, Ford specified that the distributor's vacuum advance be hooked to manifold vacuum and not the ported vacuum on the carb? It was news to me!

http://www.fordification.com/tsb/viewto ... ?f=2&t=360