OK - there is a fuel filter on the plug on the bottom of the tank as you have found on US trucks - the line for fuel pickup goes into the center of the filter, and the filter and plug unscrews as a unit. If the filter is that cruddy and you can find one - replace that filter. The best way to remove the fuel pump is to remove the carb, but that can create a whole new set of problems. It has been many years since I removed one with the carb in place, but if you bump the starter to change the lobe on the cam for the pump, it can come out without removing the carb. The 2 square pieces on the top of the tank are for the evap system, and the round unit on the side of the tank is the sending unit. Don't bother trying to find one at a parts store - Mike Warme on here is the only one that has the right parts - I bought one from him, and they are genuine Mitsubishi.