Fuel Limit Vent Valve
To meet On-board Refueling Vapor Recovery (ORVR) requirements, the fuel tank and associated components are designed to minimize fuel vapor loss during refueling. This is achieved by preventing fuel vapor from the fuel tank venting directly to the atmosphere. Fuel vapor is directed into the evaporative emissions canister where it is stored before being purged at intervals to the engine's intake manifold. For additional information, refer to: EVAPORATIVE EMISSIONS .
| ITEM | DESCRIPTION |
|---|---|
| 1 | Jet pump connection - left (passive) side of fuel tank |
| 2 | Electrical connector |
| 3 | Electrical connector |
| 4 | Fuel Fired Booster Heater (FFBH) supply connection |
| 5 | 7. Pipe connection - evaporative emissions canister to purge valve |
| 6 | Locking ring |
| 7 | Fuel supply connection |
| 8 | Fuel inlet filter |
| 9 | Fuel level sensor float |
| 10 | Swirl pot |
| 11 | Fuel level sensor 'A' |
The fuel pump module is located in the right side of the tank, and is secured to the bottom of the tank with a welded bayonet-type locking ring. The fuel pump module flange is sealed to the tank with an O-ring and secured with a locking ring.
The top flange of the fuel pump module assembly provides the internal and external interface for the tank electrical and fuel connections. The flange is formed with two external electrical connectors that are connected to the two fuel level sensors (A and B), and the in-tank fuel pump.
The lower part of the fuel pump module forms the fuel swirl pot, and provides the location for the in-tank fuel pump and the two jet pumps. The swirl pot provides a constant reservoir of fuel for the engine drawn fuel supply. The engine fuel supply line is immersed in the delivery pot.
The pump ensures sufficient fuel is in the swirl pot to supply the engine's High Pressure (HP) fuel pump demands by supplying the fuel to power the jet pump venturi's. The rapid flow of fuel through the venturi nozzle creates a depression which draws fuel back across the saddle from the left (passive) side of the tank into the pump (active) side of the tank. The second venturi draws fuel from the pump side of the tank into the swirl pot. Surplus fuel entering the fuel swirl pot overflows into the usable right side of the fuel tank.
A modified fuel pump module is installed for cold climate market vehicles that feature a Fuel Fired Booster Heater (FFBH) and an auxiliary fuel pump. The modified fuel pump module incorporates a separate fuel supply line that connects to an auxiliary fuel pump, mounted on the exterior right side of the fuel tank. An additional fuel line connects the auxiliary fuel pump to the FFBH fuel inlet.