Acceleraor pump jets dripping during closed throttle/ idle (weber dcoe).

[Classic_King]

My original thread was deleted I think because of the title or something but here’s my question anyway.


Acceleraor pump jets dripping during closed throttle/ idle (weber dcoe).

Whats the most likely cause? The check balls in the circuit look ok. Could it be the accelerator pump intake/discharge valve? Though they seem to be ok (can only blow through one way).

If the fuel bowl was flooding doesn’t it usually overflow out the venturi?

I realy need to solve this.

Any help appreciated.

[jb_22]

My bet is it's likely a perished accelerator pump diaphragm, which is used to pump extra fuel in when you first put the foot down. They usually cost about $15-20. I had to replace mine on a 32/36 Weber.

Cheers, Jess

[allencr]

If the fuel bowl was flooding doesn’t it usually overflow out the venturi?

Sure it would but the ragged, ready to conk out idle would be the first thing you'd notice, how's it idle? The check valves are simple, they are normally open in the same direction as the flow from the float bowl to the jet in the throat.
Blow through setup putting pressure in the float bowl, I think you'll live with it.
I don't think it can vibrate out, but is it Vibrating a whole lot?
Is there a hole in the throttle plate that puts a vacuum sucking right at the pump's nozzle?

[pro_k]

What fuel pressure does it have?

[Classic_King]

Yeah it idles pretty bad.

Played around with fuel pressure as low as 2psi.

So fuel defiantly doesn’t overflow the bowl via the pump jets?

Then I can rule out needle and seat or float being the problem. I’ll recheck them anyway.

[allencr]

Yeah it idles pretty bad.

...needle and seat or float being the problem. I’ll recheck them anyway.

Look at the fuel level through the jet well, I forget whether you'll have to remove the main/emulsion/air, and you'll see what it's really at, about 5-10mm below a float that's set at 10.