Seville V8-300 4.9L (1991)
Fuel Pressure Regulator: Description and Operation
Fuel Pressure Regulator Assembly
The Pressure Regulator Assembly is a diaphragm-operated relief valve having fuel pump pressure on one side and regulator spring pressure and intake
manifold vacuum on the other. The function of the regulator is to maintain a constant fuel pressure differential across the injectors at all times. The
pressure regulator compensates for engine load by increasing fuel pressure as engine vacuum drops. The pressure regulator is mounted on the rear fuel
rail and is serviced as a complete assembly.
If the pressure regulator supplies pressure which is too low (below 230 kPa or 33.4 psi) poor performance, Code E44 or detonation could result. If the
pressure is too high, rich operation, plug fouling, Code E45, poor fuel economy, and excessive odor may result.