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Holley carb dripping

gick70

Sr. Member
Joined
Jan 30, 2011
Messages
549
My carb was running great,but then the idle went goofy,hard to keep a good idle! Went home,popped the hood and the vacuum secondary rod had gas dripping off of it onto the intake! Called Holley ,they said replace your accelerator pump,ok 10.00 I will give it a try. Well my tach was acting very strange lately too. I had this other Holley carb laying around,so I put it on,so now this carb runs good,and my tach works like it should? Do I have some kind of vacuum problem with my other carb that was affecting the tach?
 

sanndmann3

Contributor
Bronco Guru
Joined
Jun 13, 2007
Messages
1,790
I think your gas dripping issue is due to the inlet needle and seat. Dirt can get stuck between the 2 causing fuel to overflow. If the needle and seat is old, it should be replaced. If its relatively new, you can try flushing it to remove any dirt that is preventing a good seal.
 

DirtDonk

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Nov 3, 2003
Messages
49,236
And your carb change had nothing to do with the tach unless you bumped a wire, or disconnected it and put it back together and now it's just working better.

Nothing with the intake will effect the tach's actual function, but if all you were seeing was the erratic behavior of the engine being indicated by the tach, that could have improved with the new carb for sure.
Depends on what you meant by "acting strange" I suppose.

But hey, it's working now! Don't jinx it!;D

Paul
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,213
The Holley vacuum secondary diaphragm has no connection to gasoline. Is the fuel coming from the secondary throttle shaft? As Paul said an electric tach shouldn't be effected by the carb.
 
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gick70

gick70

Sr. Member
Joined
Jan 30, 2011
Messages
549
What about the vacuum that comes from the distributor,to the carb,which is connected to the tach?
 

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,641
Your sig says you are a contributor can you post a pic of where exactly it was leaking? As someone noted there is no fuel in the secondary diaphragm or circuits. A leaky accel pump will not impact idle steadiness.

When the idle suddenly gets funny it is usually a vacuum leak. Maybe you had a loose hose that you put in tight when you swapped carbs?

Your tach was just showing you the wandering idle or was it actually not working?
 
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gick70

gick70

Sr. Member
Joined
Jan 30, 2011
Messages
549
Tach was working sort of counterclockwise instead of clockwise! I google the dripping from the secondary linkage,and there where people with the same problem but didn,t put the solutions!
 

DirtDonk

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Nov 3, 2003
Messages
49,236
What about the vacuum that comes from the distributor,to the carb,which is connected to the tach?

This is why we need pics. Never heard of a "vacuum operated tachometer" so we may be talking about completely different things. No hose from a carb to a tach. Only electrical from ignition to tach.

So yeah, pics might clear it all up and we can hopefully give you some useful hints.
Too bad the other discussions did not end in a solution either, but again, I don't know who would be talking about vacuum and tach in the same sentence.

But going backwards does seem odd, no matter what the drive method!

Paul
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,213
The vacuum hose to the distributor's vacuum advance is served by what is called a ported vacuum source. On Holleys that is a nipple high on the right side of the metering body. There should be no vacuum at idle. The port supplying this circuit is above the throttle plate and only gets vacuum when the throttle is opened. How this circuit effects a tach is beyond me.
Fuel spills from the booster venturis when it boils or percolates during a hot soak. It falls on the throttle shaft and migrates out the end. This would be at the bottom of the secondary rod below the diaphragm. It's the only source of fuel to get on the secondary rod that I can think of. The secondary vacuum source is just below the venturis and is initialized by air velocity passing through the venturi. The fuel as I said, is introduced by the booster venturi that ends below the secondary port. Fuel can't get in above or below the diaphragm.
 

sanndmann3

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Jun 13, 2007
Messages
1,790
I still think its the needle and seat for the fuel bowl. Take it apart, clean it out and try putting back together. Set the float level correctly and see if that cures the problem.
Good luck. :)
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,213
Holleys have sight plug in the right side of the float bowl. They are usually a brass slot head screws, until some late versions sold with a clear plastic sight plug. The proper fuel level is at the bottom of this hole. If the needle and seat are not sealing, fuel will come out of this hole, even if the float level is lowered with the engine running.
 
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