'84 Quadrajet Bowl Venting

[Stepperado]

Long story short.............

If I undo the metal fuel line leading to my carb and depress the little check valve built into the fuel filter, fuel shoots out like it's coming from a Super Soaker.

Now I fully expected fuel to dribble out, but it shot out like there was pressure in the fuel bowl.

I am not familiar with Quadrajets, I have always played with Holleys, but shouldn't the bowl be vented to atmosphere? What could be going on here?

I have a feeling this is why after sitting over night my truck acts like it's out of fuel when I go to start it. I think the pressure eventually causes fuel to get past any imperfection in the check valve seat and it drains my fuel bowl.

Let's hear it boys, give it your best shot!

Thanks,
Stepperado

 

[Jarhead79]

Look up Quadrajet Power on here, he's the expert on these carbs

 

[Quadrajet Power]

Thanks for the mention.
if you have that type of filter, you should have some pressure if you release it and the bowl is full. That would indicate that the seat is sealing up and holding the pressure.

Several things can be cause of hard start. The bowl can drain down or evaporate pretty quickly, especially if the float level is low. Ethanol fuels evaporate quicker also.

That carb has a vent system on the upper front which should vent to a charcoal or other canister. It only vents fumes.

Hope this helps.

 

[Stepperado]

Hey, good thought on that float bowl level. I know this thing is out of gas. It can sit all day long at work in the cold and it still starts instantly and goes to idle. But boy, let is sit over night and it's a different story.

Good stuff, I'll check it out.

Thanks