New Gas Cap has me confused?

[Beach-Burban]

Recently installed Edelbrock Pro Flo 4 EFI and Fuel Sump Pump to my ‘72 Suburban, which calls for a vented fuel system. I removed the charcoal canister and utilized the factory vent line that went to it (as suggested by Edelbrock) and replaced the factory “Vacuum Pressure” gas cap with a “Vented” cap…but there is still a noticeable “whoosh” sound when I remove the cap after driving it? Am I overlooking something? Any advice would be appreciated.

Woody

[71CHEVYSHORTBED402]

My 72 did that once or twice, with a new cap. I replaced it with one of these. Same was on my 71 with the vapor can removed.

What does Edelbrock say to do with the vent line?

[Beach-Burban]

Originally Posted by 71CHEVYSHORTBED402

My 72 did that once or twice, with a new cap. I replaced it with one of these. Same was on my 71 with the vapor can removed.

What does Edelbrock say to do with the vent line?

Thanks for the response, Tony…this never happen when the canister was hooked up (even when using the factory “Vacuum Pressure” cap?), but it was a QJet then. Edelbrock said to run the vent hose from their Fuel Sump Pump directly to the hardline that the canister used to run to (located down on the frame, close to the radiator). They call it a “vent”, and specifically say that a “return” is not required.

Woody