surging, backfiring

[Gezz]

so friend has a 78 bus with single 2 barrel weber, electric fuel pump and a combination fuel filter/regulator with glass bowl. Bus was running perfect until filled up and then started missing/surging. I looked at it and the fuel filter was clogged. Changed the filter and it ran great for about 30 minutes and then same thing occurred. Went back and found water in the gas in filter. Drained out all the gas, put in fresh gas, now problem remains, barely running. Has me stumped? pulled the weber filter and it is clean. Bad pressure regulator, pump tested and it is fine. thanks for any help here.
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Beachside Mechanic
69 Double Cab
73 Thing
2015 New Beetle Convertible

[dodger tom]

try adding a bottle or two of heet. that cured my water-in-the-gas problem.
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1978 Champaign Edition 2 Westfalia
Would never find the time to keep up another classic air-cooled.

[timvw7476]

& the fuel filter? If it is paper/fiber element, the water that ran in swells the fibers. Choking off flow, maybe forever. New element when a load of water is in the tank. : (

[Gezz]

filter was replaced and all the old gas purged from the tank, thanks.
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Beachside Mechanic
69 Double Cab
73 Thing
2015 New Beetle Convertible

[aeromech]

Gravity feed the carburetor from an external fuel tank and see what happens
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Lead Mechanic: San Diego Air and Space Museum
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VW type 1 1962,63,65,69,72
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[Gezz]

I did plan on eliminating the filter/regulator, checking the pressure output on the pump (which I know works as I used it to empty the tank) and if the pressure is below 3, hook it temporarily to the carb directly. Gravity feed may be easier and quick diagnostic. thanks for the advice
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Beachside Mechanic
69 Double Cab
73 Thing
2015 New Beetle Convertible

[Xevin]

That carburetor is known to be sensitive to very fine dust. I would take the carb apart and blow out every orifice. It worked for me. Are you familiar with cleaning carburetors? I probably have some info saved if you need. I like to have a spare gasket on hand or just replace the gasket when I pull a carb. It doesn’t take long to pull off, disassemble, clean, and reinstall,,,,,the second time you do it
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Keep on Busin'

[Gezz]

Yes, have rebuild thousands of carbs, it was also on my mind that something could have reached the carb. The regulator filter was really badly fouled with crud. Not sure how good the little brass mesh filter is inside the carb. thanks
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Beachside Mechanic
69 Double Cab
73 Thing
2015 New Beetle Convertible

[mikedjames]

Maybe worth taking the carburettor off and emptying fuel and water out of it. Especially the power valve well under the fitting in the bottom of the float chamber, and pump the accelerator repeatedly to clear the accelerator pump..

We always used to have trouble buying gas for outboard motors from a local marina because it rained regularly into the storage tank feeding the pump at the fuel pontoon. Water got everywhere and messed up the fuel injection system.
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Ancient vehicles and vessels

1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.

1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy

[Gezz]

this is the filter/regulator after I replaced the internal filter element.
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Beachside Mechanic
69 Double Cab
73 Thing
2015 New Beetle Convertible