mfi fuel filter console pressure reg valve

[chauser]

Hi

I was replacing fuel lines on a 2.4S MFI fuel filter console, and when I removed the return line to the tank with pressure reg valve in it I heard air entering system which seemed surprising?
Is this normal, does it indicate the tank vent is plugged, or something else?

Charles

[Jonny042]

Probably just fuel draining back to the tank - once you opened the system at the high point it would tend to happen.

[r lane]

I think the tank vent is nothing but a nipple coming off the top of the tank, no baffle or plenum. The only common restriction in that system, barring a catastrophic fuel contamination issue, is the mesh screen finger in the tank on the delivery line. Never thought about how sealed the fuel system needs to be in terms of it holding pressure when sitting. I think it is sealed as if I have the fuel lines off for any reason, I have to bleed them at the injectors to get it up and running. Bob