Fuel Pressure Release
WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
Install Fuel Pressure Gauge (49-UN01-010) to fuel pressure relief valve (Schrader valve) located on fuel rail. See Fig 1 . Place fuel pressure gauge drain hose in suitable container and release fuel pressure slowly.