Fuel Pump Delivery Quantity, Checking

Special tools and workshop equipment required 

• Remote control (jumper).
• Multimeter.
• Electrical connector test lead set.
• Fuel pressure test set.
• 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.
• Ignition switched OFF.

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK 

Start diagnosis 

-- Remove the fuel filler cap from fuel filler tube.

-- Remove right rear seat. Refer to the Repair information.

-- Remove the right cover from the fuel delivery unit.

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

-- Connect a hand held remote control (jumper) to terminal of the fuel delivery unit and to vehicle Battery positive.

-- Connect a jumper wire from terminal of the fuel delivery unit to vehicle Ground.

-- Disconnect the fuel return line -1-. Press in securing ring to disengage the fuel lines.

-- Connect a fuel line from the fuel pressure test set to the disconnected fuel return line and hold it in the measuring container.

-- Connect pressure gauge with double connection from adapter set to fuel supply line.

-- Open shut off valve of pressure gauge set.

-- Operate the fuel pump. Slowly close shut off tap, until pressure gauge shows 4 bar. From this point on do not move position of shut off tap.

-- Empty measuring container

-- Delivery rate of Fuel Pump is dependent on battery voltage. Therefore, connect multimeter to vehicle battery using adapter cables from connector test kit

-- Operate fuel pump for 30 seconds and measure battery voltage.

-- Compare the quantity of fuel delivered with specification.

1) Minimum delivery cm3 /30 seconds

2) Voltage at fuel pump with engine off and pump running (approximately 2 Volts less than battery voltage)

-- Example: During the test, a voltage of 12.5 volts is measured at the battery. Since the voltage at the pump is approximately 2 Volts less than battery voltage, there is a minimum delivery rate of 1, 200 cm3 /30 s.

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

• Fuel lines pinched or restricted.
• Restricted fuel filter.

-- If necessary, repair any pinched or restricted lines.

Check the fuel filter and replace if restricted.

-- Test the delivery quantity again.

If minimum delivery rate is not obtained:

-- Replace the fuel pump. Refer to the Repair information.

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

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

Final procedures 

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .