Hyundai Accent 94

who knows how I can repair a gasoline pump and how to know what the cables are to connect

Fuel pumps are not repaired, they are replaced!! as are the pre-filter and hoses. The wiring connections are made with a connector; the wires are identified by their color: generally: red: 12V and black: ground. Important: the connections of the lines must be very secure.

It's true, fuel pumps aren't repaired, only the diesel ones; it's better to just replace them. Identifying the wires is very simple; on these pumps there are only two: one for the pump, one for power, and one for ground. There's not much to get lost in. Besides, the pumps usually have a positive mark on their connector.