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Carb flooding while parked


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#1 metalmonkey47

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Posted 06 February 2012 - 10:07 PM

I've noticed a progressing issue on my Weber that I've narrowed down to flooding.

When I drive the truck and warm it up, after I turn it off and let it sit for 20 or so minuets, I can't start the truck up without holding it at a high idle because the carb is flooded. Takes about 15 seconds to start her up and isn't driveable for another 30 seconds after start.


I didn't have this issue before the Weber was put on a few months back, and it's only progressed since then.




My return line isn't clogged, but I'm thinking the bowl is flooding and forcing excess fuel out with the truck off? Not 100% so a little input would be nice. I don't want to go playing with float adjustments and screw myself even more.





I'll get a video tomorrow so you guys can see what I'm dealing with.

...seems to me we are being held hostage by these candy-ass pussy, limp wrist, hanky twisting, girly-man, cry when Forrest Gump's mom died, crystal gazing, Om chanting, sandal wearing, whiny voiced, oh I broke a nail, fucks.


#2 ggzilla

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Posted 06 February 2012 - 11:14 PM

Flooding is generally caused by either the float or the needle & seat. Which the float controls. So I'd say it's time to pull off the cover and examine it.

Another cause could be a block air bleed allowing the fuel to siphon, but that would cause it to run quite rich.
Here today gone tomorrow

#3 I'm BLUE

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Posted 07 February 2012 - 05:25 AM

If running electric fuel pump ... check pressure ... 2.5-3 psi is what Weber's need i believe? ( tired Atm) ... anymore will cause issues.... if running mechanical pump this shouldn't be an issue ... but if electric chances are you need a regulator for sure! Cheaply made regulators don't do shit ... rebuilt or not ... and a lot of electric fuel pumps perform different than indicated ....

Also ... longshot ... possible sunk float?

Vacuum leak in carb? Or near...

Check your points gap as the more pitted/out of gap ... the harder to start! Will simulate a flooded or rich running carb....

In addition to what ggzilla said :)

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#4 metalmonkey47

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Posted 07 February 2012 - 12:36 PM

Since the carbs literally been pressure cleaned through every passage, then I'd say that without a doubt this is a float level issue. No vac leaks, electronic ignition, and stock fuel pump so i don't think we have anything else to worry about.

Just wanted input before I went screwing with the weberPosted Image




Here's a video of the issue. Sounds like flooding right?:





...seems to me we are being held hostage by these candy-ass pussy, limp wrist, hanky twisting, girly-man, cry when Forrest Gump's mom died, crystal gazing, Om chanting, sandal wearing, whiny voiced, oh I broke a nail, fucks.


#5 ggzilla

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Posted 07 February 2012 - 11:19 PM

Sounds normal.

Here's what came with new Datsuns:

Depress the pedal about halfway and hold while cranking the engine


Posted Image
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#6 ggzilla

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Posted 07 February 2012 - 11:25 PM

The return line doesn't vent the carburetor. It only vent the fuel tank.

Starting in 1980, the Charcoal Canister vents the Hitachi carburetor. Before that they vented to the air cleaner.

Weber carbs vent to the air cleaner.


didn't have this issue before the Weber was put on a few months back

Yes I've heard a lot of complaints about Webers. Did you keep the stock Datsun carb heat shield? My guess is that the carb is heating up. It should use the stock Weber thick insulator/gasket (about 1/4" thick) and use a heat shield.
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#7 620Turbo4X4

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Posted 03 April 2013 - 08:07 PM

I have the exact same problem. I think it is todays gas. I've had Datsun 620's with weber carbs since the late 80's and never had problems like I have today. 

 

Just bought a 78 620 4X4 and it it is doing the same thing yours is. Once sitting for about 5 minutes after driving, the gas boils inside the float bowl and overflows down into your intake. I've seen mine doing it. 

 

I assume you have the exhaust manifold that is bolted to your intake like mine? Get rid if it….

 

If you can find a older intake and exhaust that not bolted together that should help a lot…. But then you may end up with the problem of my other 620 that has a 32/36 weber, edelbrock intake and header. It mysteriously looses all is fuel in the bowl when it sits for more than 3-4 days…. I had no idea that fuel, siting in a bowl, can magically just disappear. I've actually thought of filling the float bowl and bringing the darn thing in the house to watch and see where the heck the fuel goes!!!



#8 Dguy210

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Posted 03 April 2013 - 10:43 PM

But then you may end up with the problem of my other 620 that has a 32/36 weber, edelbrock intake and header. It mysteriously looses all is fuel in the bowl when it sits for more than 3-4 days…. I had no idea that fuel, siting in a bowl, can magically just disappear. I've actually thought of filling the float bowl and bringing the darn thing in the house to watch and see where the heck the fuel goes!!!

I vote a combination of inadequate heat shielding and today's gas (Ethanol). I've heard of the exact same thing on several different Weber's from several different people. I have the heat shield and a spacer on mine and I still had it happen a couple of times myself on 100F+ days.

#9 Dirttrack510

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Posted 03 April 2013 - 11:10 PM

Not to get off subject, but mine gets either vapor locked or flooded (not sure which) when I sit still in traffic for long durations of time, I'm betting my issue is due to having no heat sheild for the carb though. It clears up though if I pull over to the side of the road and shut it off for about 15 minutes and let everything cool down a bit.



#10 620Turbo4X4

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Posted 05 April 2013 - 10:08 AM

Not to get off subject, but mine gets either vapor locked or flooded (not sure which) when I sit still in traffic for long durations of time, I'm betting my issue is due to having no heat sheild for the carb though. It clears up though if I pull over to the side of the road and shut it off for about 15 minutes and let everything cool down a bit.

That almost sounds like your carb is icing up. Carbs can get quite cold during high vacuum low air flow conditions.

 

Is it worse on cold humid days?