Fuel Rails
Fuel Rails and High Pressure (HP) Fuel Lines
| ITEM | DESCRIPTION |
|---|---|
| 1 | Fuel rail balance pipe |
| 2 | Supply pipe to Bank 1 fuel rail |
| 3 | Supply pipe to Bank 2 fuel rail |
| 4 | Fuel rail - Bank 2 |
| 5 | Fuel Pressure Control Valve (PCV) |
| 6 | Supply pipe to fuel injector (6 off) |
| 7 | Fuel Rail Pressure (FRP) sensor |
| 8 | Fuel rail - Bank 1 |
Low Pressure (LP) Fuel Lines
| ITEM | DESCRIPTION |
|---|---|
| 1 | High Pressure (HP) fuel pump fuel return tube |
| 2 | Bank 2 fuel injector leak-back tube |
| 3 | Fuel rail Pressure Control Valve (PCV) fuel return tube |
| 4 | Fuel return connection to fuel cooler |
| 5 | Bank 1 fuel injector leak-back tube |
Two fuel rails are used with each rail supplying high pressure fuel to 3 fuel injectors.
Each rail has 5 threaded connections which provide for the attachment of the HP fuel supply from the HP fuel pump, the balance pipe and connections for the 3 injectors supplied with fuel from that rail.
The fuel pressure in the rails is detected by the FRP sensor which is located in the front of the Bank 1 fuel rail. The Bank 2 fuel rail houses a fuel rail PCV. The ECM controls the fuel rail PCV using signals from the FRP sensor. Fuel released by the fuel rail PCV flows into the LP fuel return line.
The FRP sensor is a piezo-resistive type sensor containing an actuating diaphragm. Deflection of the diaphragm provides a proportional signal (output) voltage to the ECM, dependant on the fuel pressure within the fuel rail.
Both rails are connected together with a balance pipe which ensures the pressure in both rails is equal, even though each rail is supplied from a different pumping element in the HP fuel pump.