Fuel Delivery Rate, Checking

WARNING: This page is about a different car, the 2009 Volkswagen Rabbit, 2008 Volkswagen Rabbit, 2007 Volkswagen Rabbit, and 2006 Volkswagen Rabbit. However, it is still accessible from the selected car via links, so may be relevant.

The voltage supply is OK.
The fuel pressure regulator and holding pressure are OK. Checking, refer to FUEL PRESSURE REGULATOR AND RESIDUAL PRESSURE, CHECKING .
The fuel filter is OK.

-- Remove the rear seat bench. Refer to "Rear Seats" in Removal and Installation .

-- Remove the cover from the fuel delivery unit.

Fig 1: Identifying Cover From Fuel Delivery Unit

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- First, pull on the connector -arrow- without pressing the retainer to make sure it connected securely. If the connector was not connected correctly, it could cause a fault.

Fig 2: Identifying Fuel Pump Control Module Connector

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Disconnect the connector -arrow-.

-- Check the contacts on the connector and the fuel delivery unit for damage.

-- Connect the test instrument adapter/DSO (5-pin) VAS 5565 between the connectors on the fuel delivery unit and cover.

Fig 3: Connecting Remote Control V.A.G 1348/3A To Test Instrument Adapter/DSO (5-Pin) VAS 5565 And To Battery Plus (+)

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the remote control V.A.G 1348/3A to the test instrument adapter/DSO (5-pin) VAS 5565 and to battery positive (+).

NOTE:

This step allows the fuel pump to run when the engine is not running.

The fuel pump delivery rate is measured at 4 bar. Check the fuel pressure before measuring the delivery quantity. Refer to FUEL PRESSURE REGULATOR AND RESIDUAL PRESSURE, CHECKING .

WARNING:

The fuel supply line is under pressure. Always wear protective eyewear and protective clothing to prevent injuries and fuel from coming in contact with your skin. Wrap a cloth around the connection before disconnecting a fuel hose. Remove the hose connection carefully to release the pressure.

-- Disconnect the return line -1- from the fuel pressure regulator. Disconnecting the couplings, refer to COUPLING, DISCONNECTING .

Fig 4: Identifying Adapter VAS 6550/1 Connected To Fuel Pressure Regulator

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the hose VAS 6550/1 to the fuel pressure regulator and hold the other end of the hose in a measuring container.

-- Operate the remote control V.A.G 1348/3A approximately 5 seconds to fill the fuel filter.

-- Empty the measuring container.

-- The fuel pump delivery rate depends on the voltage. Connect the multi-meter V.A.G 1715 to wires -1 and 5- of the test instrument adapter/DSO (5-pin) VAS 5565.

Fig 5: Identifying Multi-Meter V.A.G 1715 Connected To Wires And Of Test Instrument Adapter/DSO (5-Pin) VAS 5565

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Operate the remote control for 30 seconds and measure the voltage.

-- Compare the quantity of fuel delivered with the specification.

Fig 6: Fuel Quantity Graph

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

*) Minimum delivery rate cm³ /30 s

**) Voltage of the fuel pump with engine running in idle and the pump is on.

Example:

During the test, a voltage of 10.5 volts is measured. This results in a minimum delivery quantity of approximately 580cm³ /30 s.

If the specification is not obtained:

-- Check the supply line to the filter for possible restrictions (kinks) or clogging.

If the fuel line is OK:

-- Remove the cap from the fuel filler neck and repeat the test. If the fuel delivery quantity is now reached, check the fuel tank ventilation.

If the specification is again not obtained:

-- Check the fuel filter as follows:

WARNING:

-- Disconnect the fuel supply line -arrow- from the fuel filter. Disconnecting the couplings, refer to COUPLING, DISCONNECTING .

Fig 7: Identifying Fuel Supply Line At Fuel Filter

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the pressure tester VAS 6550 to the fuel supply line using the hose VAS 6550/1. Hold the other hose VAS 6550/2 in a measuring container.

Fig 8: Identifying Pressure Tester VAS 6550 Connected To Fuel Supply Line Using Hose VAS 6550/1

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Make sure the drain is closed and the shut off levers are open.

-- Operate the remote control V.A.G 1348/3A. Slowly close the shut off lever -A- until the pressure tester reads 4 bar. From this point on do not move the position of the shut off lever.

-- Empty the measuring container.

-- Repeat the fuel delivery test.

If the minimum delivery rate is now obtained:

-- Replace the fuel filter.

If the minimum delivery rate is again not obtained:

-- Remove the fuel delivery unit and check the fuel strainer for contamination.

Only when up to now, no malfunction has been detected:

-- Replace the fuel delivery unit. Refer to FUEL DELIVERY UNIT/FUEL LEVEL SENSOR .

-- Reconnect all disconnected fuel lines.

-- Bleed the fuel supply system.

If the delivery rate has been obtained, but malfunctions are still suspected in the fuel supply (for example, intermittent loss of fuel supply):

-- Check the fuel pump current draw. Refer to CURRENT DRAW, CHECKING .