Charcoal Canister leaking fuel following fuel tank swap

[buggalo_bill]

Hi all,

Replaced the fuel tank on my 1990 Pickup (V6) as well as corroded sections of fuel line/EVAP line. Once fueled up (only filled to half tank) and driven for ~20 minutes the truck started acting fuel starved and fuel began pouring out the air intake on the bottom of the charcoal canister. Loosened the fuel cap and there was a tremendous amount of pressure built up inside the tank. Once pressure was released the canister stopped leaking fuel. Stock fuel cap, but cap designed to relieve tank vacuum and wouldn't be a factor here as far as i understand.

Is this simply a case that the fuel vapor had previously been escaping via rust holes in the fuel tank/lines and now that the fuel system is airtight I have uncovered a clogged charcoal canister or malfunctioning TVV valve?

Tomorrow I will doublecheck that EVAP and fuel return lines have not been reversed when I assembled the new tank, as well as ensure canister lines are properly connected. Would do it now but its 4am...

Any other suggestions? Thanks!
Until I get this sorted out Ill resort to driving around with a loose fuel cap.

Happy Trails

[buggalo_bill]

Yup, I screwed up and mixed up the EVAP and fuel return lines...essentially converting the fuel tank into a kick-ass supersoaker blasting out through the charcoal canister.

Given the canister a thorough cleaning with compressed air, hopefully one instance of fuel overflow won't destroy the charcoal. Good thing this isn't my day job...