This is a weird one, and I couldn’t find any info when searching.

I finally fixed the “draining bowl” issue and now I have the opposite problem.

The truck ran great for about a year, and then I noticed that gas would slowly fill past the sight glass after I parked the truck.

It stays at the perfect level while running and right when turned off.

Any idea what could cause this? My only guess would be it’s siphoning what’s left in the pump, but the carb vent seems to be working fine.

I checked both accelerator pumps thinking they might be leaking and then draining back in, but they look good and seem to hold vacuum.

Thanks.

 

Check the operation of the fuel cut solenoid (see diagram). You can pull it off, and connect it directly to the battery to verify operation. It has a tapered pin , which is drawn back into the solenoid's body when voltage is applied, as it is when the key is in the Run position. The pin is allowed to return forward, into the carb body, when the voltage is shut off. Check that there is voltage on it's plug with the key in Run, and none at any other time.
When the pin is in the carb body, it shuts the fuel supply off, and when retracted, it allows the fuel to flow. It's main purpose is to prevent dieseling after shut down of the engine, but it also prevents the siphoning you're seeing.


Solenoid is gripped by the fingers in the picture.

BE CAREFUL!!!
The pin is driven out of the solenoid body with great force. Keep body parts, like fingers, well away from the pin!!!

Is this any help?
Pat☺

 

I agree with Pat. Check the fuel cut solenoid first.

Out of curiosity, what was causing your fuel bowl drain issue?

 

I put a new one in a couple of years ago. I’ll definitely check it again. I may need to look at a drawing of how the low idle circuit runs, but I’m having a hard time thinking how that would cause off engine flooding. Not saying it couldn’t though. Thank you.

 

it was leaking up and out of both venturis and into the manifold. I confirmed this with the carb on the truck and on the bench. I leveled the bowl off with gas and put a couple of drops of fuel dye that can only be seen with an infrared light and let it sit for 4-5 hours. Both times you could see the glowing green dye coming out of the venturis. They both had bad o-rings. I replaced with tighter vitro o-rings, tested it again and it stopped.

That makes zero sense to me, but it’s what it was.