Suction Jet Pump (4WD Only), Removing and Installing

Suction jet pump, removing and installing

On vehicles with all wheel drive the shape of the fuel tank dictates that a suction jet pump is required to pump fuel to the fuel delivery unit from sender 2 area. A second suction jet pump ensures the delivery unit in the reservoir is supplied with fuel. The suction pumps function according to a principle of physics using the return flow of fuel via a junction with pressure limiting valve.

Note:
A check is only necessary when:
- the engine stops due to lack of fuel
- error 00561 is stored in DTC memory although the fuel gauge shows that the tank is still 1/4 full.

Test conditions
- The 3 senders must be checked using the On Board Diagnostic program and be OK.
- Fuel tank must have been drained

Special tools and equipment



- 3087 Fuel tank sender spanner

Work sequence
- Note safety precautions before starting work, Service Precautions

WARNING!
Fuel supply lines are under pressure! Before removing from hose connection wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.

- Pull 4-pin connector and fuel hoses off fuel delivery unit (right-hand side of vehicle) and remove fuel delivery unit, Fuel Delivery Unit, Removing and Installing




- Now pull 2-pin connector off fuel gauge sender 2 -G169- (left-hand side of vehicle), open sealing ring with key 3087 and carefully lift the sender.




- Now pull off connector -1- under sender 2 cover -2-.
- Lift sender 2-2- and pull suction jet pump -3- out of locking device of sender.
- Take out sender 2.




- Now, on right-hand side of vehicle (fuel delivery unit), pull hose/line to suction jet pump -2- off junction -1-and pull connector -3-off sender for fuel gauge -G- to fuel level sensor 2 -G169-.
- Now suction jet pump can be pulled out from sender 2 side (left-hand side of vehicle).
- Check that fuel hoses/lines on suction jet pump are installed securely and are not damaged.
- Additionally, check suction jet pump for contamination/dirt if necessary.

If no malfunctions are found:
- Install suction jet pump and sender 2 again in reverse order.

Note: In other work sequences the return supply line/hose must be pulled offjunction. When doing this observe that all 0-rings must be replaced.

Check junction with pressure relief valve as follows:



- Pull off connections for return supply -2-, connections -3- and -4- for suction jet pump on junction with pressure relief valve -1-.
- Unclip junction which is secured on reservoir.
- Use a test hose and blow into connection, from direction of fuel return -2-, there must be through flow in directions -3- and -4-.
- Hold connections -3- and -4- closed, the pressure relief valve must open under slight opposing pressure.
- If no opposing pressure can be determined or pressure relief valve does not open, replace junction with pressure relief valve.