2000+ EVAP ideas: fill check valve

[Jason.MZW20]

I've been thinking over some ideas regarding the 2000+ charcoal canister and its fill check valve provision. I know of Randy Noll's remote FCV, but I had a small epiphany.

The fill check valve is really just another fuel cutoff valve and breather. It has a floater inside of it so that when the tank is full, the floater cuts off any ventilation, sealing the tank. Consider that the Camry fuel tank has 1 fuel cutoff valve and 1 fill check valve. They have different hose sizes, but they serve the same purpose. The fill check valve connects to the vent port on the charcoal canister and the 3/8" vent line next to the fuel filler hose.

Now, consider that the MR2's fuel tank has 2 fuel cutoff valves: one at the front of the tank and one at the rear. Both have EVAP tubes for fuel vapors when the cutoff floater is lowered (tank not full). These tubes are combined at the EVAP separator (the black bar with pipes coming from it at the front of the engine compartment). This connection already needs to be tee'd for the Vapor Pressure Sensor and vapor line to the canister as this is the proper route to take for the fuel vapors, since they are controlled by internal floaters (cutoff valves), just like the Camry fuel tank (this might help set the EVAP OBDII monitor faster). The return line is almost always submerged, so it's sealed and hardly sees vapors until the fuel level is below the return pipe on the fuel pump assembly. This makes the ECU think the tank is full and will retest at a later time (never a CEL). If it never sees vapors when the ECU tests it, it'll never set the monitor, I think.

Anyway, I was thinking of tee'ing the vent line, connecting the tank directly to the EVAP canister. It'll obviously need an inline conversion barb 5/8" to 3/8". But also on the vent line, I'd tee into the 2 cutoff valve connections, mimicking a fill check valve as the floaters open and close the tank as the liquid gas level changes.

Thoughts? If you need pictures, I can put some up from the service manuals.