Under the hood, under the brake fluid reservoir.
Yes, this is a fuel injected engine.
No, just replace the filter.
4 quarts with filter change
See link below
1993 Saturn sl2
Yes it is returnless and the pump regulator is integrated into the fuel filter.
Filter is located in the rear of the vehicle under car on the drivers side,
inline fuel under the car in the frame rail up front next the motor area.
== == In the fuel tank.
It is in the fuel tank.
Have you kept up on the filter and fluid changes? Is the fluid low?
In the fuel tank.