Where is the fuel pressure regulator located on a Chevy blazer s10 4x4?

The fuel pressure regulator on a Chevy S10 Blazer 4x4 (depending on the year and engine) is typically integrated into the fuel rail. It's not a separate component like on some older vehicles. You'll find the fuel rail on top of the engine, near the intake manifold. The regulator itself isn't usually easily visible, as it's part of the fuel rail assembly.