Weber carb gas flow

[kav]

Question about Weber triple barrel carbs, when you turn the key to the on position and the fuel pump primes should it come to a dead stop after priming or does gas flow through the jets and drip constantly into the venturi causing the fuel pump to click every 1 to 2 seconds if you leave the car in the key position for a minute?

Cheers,

-Kav.

[ed mayo]

Kav, there should NOT be a steady drip of gas into the throats, the needle valves should close preventing that. There may still be an occasional tick from the pump, but not enough to overcome the needle valves.

[kav]

Originally Posted by ed mayo

Kav, there should NOT be a steady drip of gas into the throats, the needle valves should close preventing that. There may still be an occasional tick from the pump, but not enough to overcome the needle valves.

Thanks Ed, looks like just cylinder #3 has quite a flow. #1 & 2 share a bowl and #3 has it's own? Looks like all the other Venturi's are dry. So the rear left needle and seat is leaking?

-Kav

[kav]

Just took a look and #2 & 3 share a bowl? If that's the case why would #3 be the only one that leaks?

-Kav

[ed mayo]

Is it dripping from the acellerator pump nozzle?

[kav]

Originally Posted by ed mayo

Is it dripping from the acellerator pump nozzle?

Original it was, the accelerator nozzles were filling up the venturi's so I adjusted the linkage and that issue went away. Then it started to drip out of the pre-atomiser tube in a heavy flow but like you suggested I looked at the needle & seats. I swapped the front for the rear and tightened them down and no more drips! Then the other side started! #4 & 6 so I did the same and they have stopped dripping.

All looks stable, I kept the key on position for 20mins and hunted for fuel leaks, it all looks dry enough but the fuel pump still clicks every 4 - 5 seconds during that whole time?? Is that normal?

Cheers,

-Kav.

[1QuickS]

I have been experiencing defective float needle valves recently. Typically I have seen defective float needle valves for 10 years at rate of 1 per 100 but lately I have seen defective needle valves at 1 per 4.

[kav]

Originally Posted by 1QuickS

I have been experiencing defective float needle valves recently. Typically I have seen defective float needle valves for 10 years at rate of 1 per 100 but lately I have seen defective needle valves at 1 per 4.

That means there's one in my car!!!

[Quickstep192]

Is your car originally carbureted?

Mine was MFI before being converted to Carbs and if not regulated properly, the pressure from the MFI fuel pump is too much for the carb float valves?

[1QuickS]

Fuel pressure at the carbs is 3.56 psi per tech specification but I suggest plus/minus 1/2 psi is fine.

Old needles will leak due to the tips will develop a ridge where they seat in the valve body.

MFI & CSI pumps have pressures too high and require regulating down to the nominal operational pressure. Most aftermarket fuel pumps "for carburetors" have fuel output pressures for domestic carbs (Holley, etc.) which is 7 psi. These need regulation also.

You can determine if you have a bad needle by moving suspect needle to another location & see if the dripping issue follows the needle.