Item name | Spare part number | Description |
1 | - | Piping connection of the purge valve with a carbon adsorber |
2 | - | Fuel tank breather tube |
3 | - | fuel pump module flange |
4 | - | Pump module clamp |
5 | - | Pump module collar |
6 | - | Pump module seal |
7 | - | Lid |
8 | - | Pipe connection - purge valve |
9 | - | Pipe connection - fuel supply line |
10 | - | Frame |
11 | - | Fuel tank |
12 | - | Fuel supply line |
13 | - | Mounting screws (6 pcs.) |
14 | - | filler hose |
15 | - | heat shield |
16 | - | Rivet |
17 | - | Screw M6 |
18 | - | clamp cover |
The fuel tank is located on the right side of the car body between the gearbox and the right side member. The tank rests on the frame, through which the fuel tank assembly is attached to the vehicle body. The working volume of the fuel tank is 86.3 liters.
The frame is attached to the chassis with six screws. When the frame is attached to the chassis, the fuel tank is pressed against the suspension cross member with foam pads. A protective cover is attached to the right front corner of the fuel tank, which provides additional protection.
The fuel tank is made of molded plastic with a minimum thickness of 3 mm. The fuel tank is a sealed unit with internal access through a pump module flange opening at the top of the tank.
The flange assembly includes the lip, yoke, and pump module flange, which contains all external piping and electrical connections for internal tank assemblies. The flange is sealed with a seal in the tank opening. For proper flange orientation, position the flange so that the arrow on the flange is between the two marks on the fuel tank adjacent to the pump module flange hole. The cuff is located above the flange and fastened with a clamp. Flange, seal, collar and collar comply with LEV2 sealing requirements.
The flange has an external six-pin connector for connecting fuel level sensors and a fuel pump. This connector is split into three tight-fit connectors on the underside of the flange. The fuel supply line and the breather are connected by a quick connector.
A support structure is installed inside the tank, designed to fasten the internal components of the fuel tank. Support structure houses fuel pump module, front fuel level sensor, flip valves (ROV) and front jet pump.
The fuel pump module consists of several assemblies. The module includes: a fuel pump, a rear fuel level sensor, a rear jet pump, a pump inlet filter, a second fine mesh filter, and a fuel pressure regulator located in a manifold that is mounted on a support structure. The pump module assembly and fuel level sensors are supplied only as an assembly, the delivery of individual parts of these assemblies is not possible.
Fuel tank internals
Item name | Spare part number | Description |
1 | - | Right front flip valve (ROV) |
2 | - | Complete support structure |
3 | - | Corrugated tube of the breather of the vent valve of the fuel tank (FLVV) |
4 | - | Corrugated tube front flip valve |
5 | - | Fuel vapor separator (LVS) |
6 | - | ROV rear right valve |
7 | - | Rear left valve ROV |
8 | - | fuel pump module |
9 | - | Rear fuel gauge |
10 | - | T cabin breather fuel tank |
11 | - | Connector |
12 | - | Fuel tank vent valve (FLVV) |
13 | - | Front fuel gauge |
14 | - | Front Left ROV Valve |
15 | - | Front jet pump |
The 4.4L V8 engine ventilation system is identical to the system used on models with a 4.0L V6 engine. The ventilation system includes:
- four flip valves (ROV)
- one fuel tank vent valve (FLVV)
- one vapor separator (LVS)
The two rear ROVs are mounted directly to the LVS with rubber grommets and secured with clips.
The two front ROVs are located at the front of the fuel tank and are secured to the base frame main stem with a plastic clip. Both ROV valves are connected to the LVS by plastic corrugated tubes.
All four ROVs are connected directly to the LVS. The liquid fuel released from the vapors in the LVS is drained back into the fuel tank through the FLVV valve. The LVS is connected to the fuel pump module flange via a corrugated tube.
Due to this, fuel vapors escape from the fuel tank during ventilation.
The main purpose of the FLVV valve is to control the filled volume of the tank. During refueling, fuel vapor passes through the FLVV valve in the LVS. The fuel vapor then flows through a corrugated tube from the LVS to the fuel pump module flange vent. The flange vent pipe is connected to a carbon adsorber, which accumulates fuel vapors. When the fuel level in the tank reaches its maximum level during refueling, the FLVV valve closes and prevents fuel vapor from passing through the LVS. This causes the pressure in the fuel tank to build up, which in turn causes the nozzle pump to shut off.
Fuel pump module
The fuel pump module is fixed to the tank support structure and is located at the bottom of the receiving cup. There are three electrical connectors on the flange of the pump module: one for connecting the fuel pump and two for two fuel level sensors. These assemblies are connected to the external electrical connector through connectors on the bottom of the fuel pump module flange.
Pump module nominal capacity is 122 l/h at 12.3 V and output pressure is 4.5 bar (65.2 lbf/in2).
The fuel pump is powered from the fuel pump relay located in the battery junction box. The relay is controlled by the engine control module and turns on each time the ignition key is turned to position II.
The fuel pump inlet filter is installed in the inlet port at the bottom of the pump. The filter has "winged" vertically on the side of the pump so that the filter part is away from the base of the suction cup to prevent premature filter contamination. The filter has a fine mesh (cell size is 31 microns) area 70 cm2 (10.8 inch2).
A second fine mesh filter is located around the top of the fuel pump. This provides additional cleaning of the fuel before it enters the fuel manifold and distributor. The filter has an electrical connection to ground. The mass is necessary to remove electrostatic charges that can occur on a fine mesh filter.
A bypass valve is also built into the fuel filter outlet to prevent fuel from returning to the pump when the engine is not running. This allows fuel pressure to be maintained in the line from the fuel supply line to the fuel manifold when the engine is not running.
Fuel level sensors
The sensor is a passive magnetic position sensor (MAPPS), the signal of which is a change in the resistance of the mass circuit of the fuel gauge. To increase reliability, the sensor is isolated from the fuel so that its contacts do not get dirty. The front and rear fuel level sensors are connected to the external electrical connector on the flange through connectors on the bottom of the fuel pump module flange.
The front sensor is mounted on the front of the fuel tank support structure and can be accessed through a hole in the fuel pump flange. The rear sensor is mounted on the side of the sump and is also accessible through a hole in the flange.
NOTE: A new tank comes complete with a front fuel gauge.
The sensor has an arc with a ceramic surface, on which 51 film resistors are installed. The resistors are connected in series through separate contacts. At a short distance above the film resistors, a soft magnetic foil with 51 flexible contacts is mounted. Under the ceramic surface there is a magnet attached to the fuel indicator float lever. When the float lever moves, the magnet moves in an arc along the film resistors. The magnet pulls the flexible contacts to opposite film resistors and completes the circuit.
The principle of operation of the sensor
Item name | Spare part number | Description |
1 | - | magnetic foil |
2 | - | Spacer |
3 | - | ceramic surface |
4 | - | Magnet |
5 | - | Resistive film |
The resistance of film resistors located along a linear arc varies in the range from 51.2 to 992.11 ohms. The output signal is proportional to the amount of fuel in the tank and the position of the float. The measured resistance is processed in the instrument panel to eliminate the influence of fluctuations in the surface of the fuel in the tank. The processor monitors the sensor signal and updates the position of the pointer pointer at regular intervals to ensure that the pointer position does not constantly change due to fluctuations in the fuel surface when braking or turning.
The control lamp in the instrument panel turns on when the fuel level in the tank is 10 liters or less.
In the instrument panel, the signal from the fuel level sensor is converted into a CAN·message in the form of a direct interpretation of the contents of the fuel tank in liters. The ECM uses the CAN·message to write additional OBD P misfire detection codes when the fuel level drops below a preset value.
Front Fuel Level Sensor Resistance/Fuel Gauge Reading Chart
NOTE: These values are valid when the vehicle is on a level surface. The fuel gauge reading changes as the vehicle tilt changes.
Fuel level sensor resistance, Ohm | Rated pointer reading |
51 | empty tank |
51 | Low Fuel Alarm |
294 | half filled |
798 | Full |
Rear Fuel Level Sensor Resistance/Fuel Gauge Reading Chart
NOTE: These values are valid when the vehicle is on a level surface. The fuel gauge reading changes as the vehicle tilt changes.
Fuel level sensor resistance, Ohm | Rated pointer reading |
75,5 | empty tank |
120 | Low Fuel Alarm |
280 | half filled |
675 | Full |
Fuel pressure control
The fuel pressure regulator is located in the manifold inside the fuel tank. The regulator maintains the necessary pressure of the fuel entering the fuel manifold through the fuel supply line by bypassing part of the fuel back to the front jet pump.
The regulator maintains the fuel pressure at the inlet to the fuel manifold at a level of 4.5 bar, and its operation depends on the pressure at the pump outlet (65.2 lbf/in2). If the pressure exceeds the specified value, the regulator opens, reducing the pressure at the inlet to the fuel manifold by bypassing some of the fuel into the front jet pump. The regulator must maintain the fuel pressure at the optimum level to ensure proper fuel injection.
Receiving glass
The cup is located at the rear of the fuel tank and holds most of the fuel pump assemblies.
The sump serves as a fuel reservoir that provides a constant supply of fuel to the fuel pump, regardless of the amount of fuel or the tilt of the vehicle. When the vehicle is on a level surface and the engine is running, there is approximately 400 cm3 in the receiver (24.4 inch3). Two jet pumps continuously supply fuel to the jet cup, ensuring that fuel is supplied to the pump.
A check valve is located at the base of the receiving cup. The valve passes fuel from the tank into the receiving cup, but does not release it back into the tank.
Jet pumps
The fuel system has two jet pumps. The front jet pump is located on a support structure at the front of the fuel tank. The rear jet pump is located in the receiving cup under the fuel pump. Both pumps operate on the basis of the Venturi effect created by fuel at a pressure equal to the pressure at the outlet of the fuel pump as it passes through the jet pump. As a result, an additional amount of fuel flows from the fuel tank into the receiving cup through the holes in the jet pump housing.
The front jet pump is mainly used when driving downhill. The jet pump is connected to the system through a pipeline from the fuel manifold, and is supplied with fuel discharged from the fuel supply line by the fuel pressure regulator. The front jet pump draws fuel from the front of the fuel tank and pumps it into the jet cup, providing a continuous supply of fuel to the pump. The jet pump has a nozzle with a diameter of 2.1 mm.
The rear jet pump operates at the same pressure as the fuel pump outlet and draws some fuel from the rear of the fuel tank.
Turnover valves (ROV)
Four ROVs are located on the fuel tank support structure and are piped to the fuel vapor separator. The separator, also mounted on the support structure, is piped to the fuel tank breather outlet on the pump module flange. rOv valves use non-return valves that close when the vehicle is rolled over, preventing fuel from escaping from the tank through the breather tube.
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