If there is not an access panel in the floor, over top of the tank, you will need to drop the tank.
Did you try pushing the reset in the back, on the left, behind the panel?
Take it to the dealer, there is an unlimted warranty on these fuel pumps as they have had many problems on them. Ford will replace them for free if need be no matter how many miles are on the car, mine was replaced at 115k.
Actually there isn't an unlimited warranty on them. I called the ford dealership for mine after I had read that there was, gave them the vin number, and they said the only thing on it was an improved warrenty on the front struts and a recall on the rear door latch.
Probably the fuel filter. Change it.
In the fuel tank.
According to the 2000 Ford Focus Owner Guide : ( 50.0 litres / 13.2 U.S. gallons )
It's in the fuel tank.
Fuel filter is cloggeg with trash from garbage gas. Change the fuel filter and... Buy Sunoco.
56 liters
4 to 6 pis
35 - 55 psi
Under the car, between the fuel pump and the injector pump.
Do NOT use Diesel fuel in a Ford Focus. The engine will stop running and you will have to drain the gas tank to rid the car of the diesel fuel. Gasoline engines are not designed to run on diesel. They do not have enough compression to cause the diesel fuel to combust The only engine used in a 2000 Ford Focus was the 2.0 which is NOT a diesel engine.
Change the fuel filter.
Drop the gas tank.