What part is this?

[MReno]

So I have an '89 GW I am working on that has the AMC360 engine. Most of the emissions hoses seem to have been cut and plugged by PO, however yesterday while trying to figure out what emissions systems I need to should keep, I manage to break a sensor that has an electrical harness connection on it. But I am not sure what part it is (see photo). It was located in line, down stream of the carb canister on the carb bowl vent line, after what I believe is the vapor separator (rusty looking metal thing in photo). Any help as to what this is and if it is needed? I am exempt from emission inspection, so deleting much of the emission stuff is just fine with me. Thanks.

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[MReno]

Is it the Carb Bowl Vent Valve? And is it required?

[sirrus]

You’re right, it is carb bowl vent solenoid. It is open when engine is off and supposed to be closed when ignition is on. It’s function is to vent gas fumes from bowl to charcoal canister to prevent excessive pressure in carb.

If you’re exempt from emissions testing and you don’t mind smell of gas from under the hood - you can get rid of it. I wouldn’t advice plugging that vent on the carb because without it there’s a chance of pressure building up in bowl and eventually flooding the engine

[tgreese]

As I understand it - When the engine is running, the bowl is vented through the pair of bowl vents on the air horn. Engine off, the door in the air cleaner snorkel closes, shutting the air horn from the atmosphere, and the bowl needs another vent. Hence the solenoid valve. May be covered in the TSM ... no time to search right now.

[sirrus]

Yeah, tgreese is right. And you should keep some way of venting the bowl for engine on and off both to prevent excessive pressure in the bowl

What I meant is that if you remove the solenoid and plug it’s vent, you need to have the air cleaner door open on engine off to still provide bowl ventilation. One downside is that it’s going to vent to atmosphere instead of charcoal canister, hence gas smell under the hood

[MReno]

Sounds like I should find a replacement part and keep it. Thanks for the input everyone.

[tgreese]

You can delete the solenoid plumbing if you provide a vent for the float bowl when the engine is off. Possible you could prop open the snorkel door and vent the bowl that way. Clearly that would not be emissions compliant, but it would be fine for operation as long as the bowl does not dry out.

[MReno]

So I plan on replacing the carb vent bowl solenoid however with much of my emission stuff removed, I am unsure where on the carburetor I should have this attached? I have an Edlebrock 1405 carb, and are currently using the PCV port for PCV, the manifold vacuum port for the distributor, and the rear brake port for my power break booster line. The only port left would be on the front, lower left that is to be used for timed vacuum, which I have capped. Any suggestions on where to connect the carb bowl vent line?

[tgreese]

I would not expect the Edelbrock to support such a vent system. Are you using the factory air cleaner?

[MReno]

I am not using the factory air cleaner.

[tgreese]

You probably have an open element air cleaner. This type of air cleaner vents the float bowl directly to the atmosphere all the time, engine running or not. Even if you could connect the vent solenoid to your carburetor, it would do nothing.

[MReno]

Yes, I am running an open "round" air filter. Therefore, replacing the vent solenoid would seem useless.

[tgreese]

Yep. With that type of air cleaner, the only thing sealing the bowl vents from the atmosphere is your air filter element. The factory air cleaner closes completely to trap any evaporating fuel and send it through the vapor recovery system (charcoal canister) via that solenoid valve.

[MReno]

Thanks for everyone's input.