Howdy, I have a 95 Civic EX automatic out here in California. Its been my daily driver for the past 45K miles. Just in the last two weeks whenever I fill up with gas, it will spray fuel back out if I fill it above 80% fuel capacity. From what I've read, an EVAP line may be clogged? Is there a particular line that is infamous on this year/make/model that someone could point me to? Any known common issues with these vehicles concerning the fuel filler? Thanks in advance.

 

Excessive pressure in the tank vents through a hose attached to the front left corner of the tank (not reachable through the access panel under the back seat), then a two-way vapor valve, also on the front left corner of the tank. The outlet of the two-way valve then goes to a metal pipe under the car that runs forward up to the EVAP charcoal canister on the firewall. This is the 49 state system, built for California may be different.

 

Maybe that 2-way valve is the problem? There is some talk about that valve in the last few pages of my build - link in sig...

 

The EVAP system is not responsible for venting displaced fumes when filling with fuel, there is a separate line (part of the filler neck) for that. During the filling, the vapor in the tank is vented through s small tube running parallel to the fuel filler neck. If you look at pictures of the filler neck (on ebay or parts digrams) you will see where that tube connects just before the top of the fill neck.

Personally I think this is a problem with the gas stations nozzle or pumping pressure. Try a different gas station and see if it persists. Fuel is supposed to back up the filler neck (momentarily) once the tank is full, that is how the nozzle knows when to auto-shut-off.

I wish I had a cut open EG tank to see exactly where all the pipes & baffling run inside.