This one has the Mazda service techs. stumped. Fuel gauge at or below 1/4 mark, pull into gas station, shut off car insert nozzle etc...Tank will NOT accept ANY fuel. (Just gushes out of fill pipe) Happened over the winter, took it in under warranty (2003 Protege with 6300 miles on it now) Mazda could not find a proplem but replaced the carbon canister as it was full of gas. (Claimed the tank was overfilled...yeah right, we could not fill the tank at all more or less overfill it!) Anyhow, problem has just recurred, same symptoms, brought it in, they can't find a problem, carbon canister is once again ruined...again from "overfilling the tank" (again not bloody likely) They insist they have taken the tank apart and "everything is fine" (How they managed to do that with out even rubbing the dirt off the bolts...) I think the one way check ball in the tank is sticking shut...what you guys think?

There is a white check valve under the car, at the left rear. If that valve plugs, it will prevent air from escaping the fuel tank, as you refuel. In the shop manual, there is information on checking the operation of that valve. Replacement is likely required. If it is removed, and has a bunch of dirt and dust in it, it is likely no good. If memory serves, you should be able to blow through it in several directions, but make sure you (or someone) checks the manual!!!