Holley 4160, vacuum secondary ?'s

[jerrys84]

after thinking about what a couple of you said a few weeks ago, it does actually sound like my secondaries aren't opening...

I checked for vacuum leaks and found none.... soo my question is, where does the secondaries get the vacuum to operate??

Is it throught the carb body or does it need a vacuum line connected somewhere???

I pulled the carb out of the box last fall, put it on the car used one of the vacuum ports to run the vac advance, and plugged the rest...

was this not correct??? the old factory carb has a short vac line that goes from the top/passengers side of the carb to a port by the choke housing, but the new carb does'nt have those ports...


help pleeze, i am really confused....

[PKRWUD]

There is a very tiny hole just below the lip of the primary and secondary venturi that are on the same side of the carb as the vacuum secondary diaphram. This is where the vacuum comes from. It is created by the air rushing into the engine. This is one reason why the vacuum secondary is so superior to the secondaries used in AFB and quadrajet style carbs. The carb will never be asked for more gasoline than the engine needs.

I'm sure you have vacuum to your diaphram, but your diaphram may be bad.

Remove the 3 screws that mount the housing to the side of the carb, and remove it. Watch for a small cork gasket right inbetween the two middle screw holes.

Push the diaphram arm up, and place your finger over the hole on the side, between the two screw holes. If the diaphram is good, the arm won't move when you release it, until you move your finger.

Take care,
-Chris