Fuel Pump Delivery Quantity, Checking

WARNING: This page is about a different variant/trim than selected.

Special tools and workshop equipment required

Hand held remote control (jumper).
Multimeter.
Electrical connector test lead set.
Fuel pressure test set (high pressure).
Measuring container, fuel-resistant.

Test conditions

Battery voltage 12.5 V
Fuel filter OK
Fuel tank at least ¹ /₄ filled.
Fuel pressure regulator OK. Refer to Repair information.
Ignition switched off.

Test procedure

-- Perform a preliminary check to verify the customers complaint. Refer to GENERAL DIAGNOSIS .

Start diagnosis

-- Remove the fuel filler cap from fuel filler t3.2 V6 4V Engine Mechanical, Engine Code(s): BUBe.

-- Remove rear seat bench. Refer to Repair information.

-- Remove cover retainers -arrows- from the right sealing flange.

Fig 1: Identifying Cover From Fuel Delivery Unit

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-- Disconnect the electrical harness connector -arrow- from the fuel delivery unit.

Fig 2: Disconnecting Electrical Harness Connector From Fuel Delivery Unit

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-- Connect a Hand held remote control (jumper) to terminal -1- of the fuel delivery unit and to vehicle battery (+).

-- Connect a jumper cable from an Electrical connector test lead set to terminal -5- of the fuel delivery unit and to vehicle Ground (GND).

Fig 3: Identifying Jumper Cable From Electrical Test Lead Set Connected To Fuel Delivery Unit Terminal And Vehicle Ground

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WARNING:

Fuel system is under pressure! Before opening the system, place rags around the connection area. Then release the pressure by carefully loosening the connection.

-- Disconnect fuel line -arrow- by pulling release button.

Fig 4: Disconnecting Supply Line And Catch Escaping Fuel Using Rag

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-- Connect the Fuel pressure test set (high pressure) onto the disconnected fuel supply line.

Fig 5: Identifying Attachment Of Fuel Pressure Test Set (High Pressure)

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-- Connect an assisting hose -arrow- on to the Fuel pressure test set (high pressure) and hold it into a measuring container.

-- Open the shut-off valve of pressure gauge. The lever points in direction of flow.

-- Generate pressure in the fuel system by pressing the remote control switch and slowly closing the pressure gauge shut-off valve.

Specification: 4 bar positive pressure.

-- From this point on do not move position of shut-off valve.

-- Empty the measuring container.

-- Press switch on remote control for 15 seconds.

-- Compare quantity of fuel delivered with minimum delivery rate in the diagram (cm³ /15s).

Fig 6: Identifying Delivery Rate Diagram

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NOTE:

Voltage at the fuel pump with engine stopped and fuel pump running is approx. 2 volts less than battery voltage.

If minimum delivery quantity is not obtained, the following malfunctions may be present:

Fuel lines pinched.
Fuel filter clogged.
Fuel pump faulty.

Assembly is performed in reverse order of removal. Note the following:

-- Install the rear seat bench. Refer to Repair information.