Section 03-04A: Fuel Charging and Controls, 4.9L Engine | 1996 Vehicles Equipped with 4.9L SFI Engines Workshop Manual |
The fuel pressure regulator (9C968) is attached to the fuel injection supply manifold (9D280) downstream of the fuel injectors (9F593). It regulates the fuel pressure supplied to the fuel injectors. The fuel pressure regulator is a diaphragm-operated relief valve in which one side of the diaphragm senses fuel pressure and the other side is subjected to intake manifold vacuum. The nominal fuel pressure is established by a spring preload applied to the diaphragm. Balancing one side of the diaphragm with manifold pressure maintains a constant fuel pressure drop across the fuel injectors. Fuel, in excess of that used by the engine (6007), is bypassed through the fuel pressure regulator and returns to the fuel tank (9002).
| Item | Part Number | Description |
|---|---|---|
| 1 | — | Engine Vacuum Reference Tube (Part of 9H321) |
| 2 | — | Ball Seat (Part of 9H321) |
| 3 | — | Spring (Part of 9H321) |
| 4 | — | Upper Housing (Part of 9H321) |
| 5 | — | Diaphragm (Part of 9H321) |
| 6 | — | Lower Housing (Part of 9H321) |
| 7 | — | Fuel Outlet Tube (Return) (Part of 9H321) |
| 8 | — | Fuel Inlet Tube (Supply) (Part of 9H321) |
| 9 | — | O-Ring Groove (Part of 9H321) |
| 10 | — | Mounting Plate (Part of 9H321) |
| 11 | — | Fuel Filter Screen (Part of 9H321) |
| 12 | — | Spring Seat (Part of 9H321) |
| 13 | — | Valve Assembly (Part of 9H321) |