Problem: If you leave the gas cap on with the Brat parked, the charcoal canister will fill with fuel and begin spilling it out the bottom of the canister.

 

Vehicle is an 86 Brat that had an 84 Turbo conversion done on it. This is not mine but its a really well done conversion. The fuel tank and pump were both swapped over.

Did you try a different gas cap?

My guess is two or more of the rubber lines to the fuel tank are connected incorrectly.

The fuel return line to the tank (as it enters the tank under the gasoline level) and the tank vapor line appear to be swapped.