Volkswagen Workshop Service and Repair Manuals

Checking fuel delivery rate, engine codes BSE, BSF, CCSA, CMXA l  Voltage supply OK. l  Fuel pressure regulator and holding pressure OK, checking → Chapter l  Fuel filter OK. –  Remove seat bench (Golf Plus: rear right seat) → General body repairs, interior; Rep. Gr.72.

–  Remove cover from fuel pump unit.

–  First check that the connector -arrow- is fitted securely by pulling the connector without pressing the catch. The connector can cause a fault if it has not been fitted correctly. –  Now pull off connector. –  Check the contacts on the connector and on the fuel delivery unit for damage.

–  Connect test instrument adapter/DSO (5-pin) -VAS 5565- to connector and fuel pump unit. –  Connect remote control -V.A.G 1348/3A- to test instrument adapter/DSO (5-pin) -VAS 5565- and to battery positive (+).   Note t  This step serves only to have the fuel pump running when the engine is stopped. t  The delivery rate of fuel pump is measured at 4 bar. Therefore, test fuel pressure before measuring fuel delivery rate → Chapter.   WARNING Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid possible injury and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.

–  Pull off return line -1- from fuel pressure regulator.   Note Press in securing ring to release fuel line. –  Connect adapter set -VAS 6550/1- to fuel pressure regulator and hold end of adapter in measuring container. –  Operate remote control -V.A.G 1348/3A- for about 5 seconds to fill fuel filter. –  Empty measuring container.

–  The quantity of fuel delivered by the fuel pump depends on the system voltage. Therefore, also connect multimeter -V.A.G 1715- to contacts -1 and 5- of 5-pin test instrument/DSO adapter -VAS 5565-. –  Operate remote control for 30 seconds while measuring battery voltage.

–  Compare quantity of fuel delivered with specification. *) Minimum delivery rate cm3/30 seconds **) Voltage at fuel pump with engine not running and pump running. Example: During the test a voltage of 10.5 volts is measured. This equates to a minimum delivery rate of approx. 580cm3/30 sec. If the specification is not attained: –  Check fuel pipes for possible restrictions (kinks) or blockages. If fuel line is OK –  Remove cap from fuel filler neck and repeat check. If fuel delivery rate is now reached, check fuel tank breather. If the specifications are still not attained: –  Check fuel filter (proceed as follows):   WARNING Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid possible injury and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.

–  Pull fuel supply line -arrow- off fuel filter.

–  Connect pressure tester -VAS 6550- to fuel supply line with adapter -VAS 6550/1-. Hold adapter -VAS 6550/2- in a measuring container. –  Make sure that drain tap is closed and cut-off taps are open. –  Operate remote control -V.A.G 1348/3A-. Then slowly close shut-off tap -A- until a pressure of 4 bar is displayed on pressure gauge. From this point on do not move position of shut-off tap. –  Drain measuring container. –  Repeat delivery rate check. If the minimum delivery rate is now attained: –  Renew fuel filter. If the minimum delivery rate is again not attained –  Remove fuel delivery unit and check filter strainer for soiling. Only if still no fault has been detected: –  Renew fuel delivery unit → Chapter. –  Reconnect all disconnected fuel lines. –  Bleed fuel system → Chapter. If fuel delivery rate has been attained, but you nevertheless suspect a fuel supply system fault (e.g. intermittent failure of fuel supply system): –  Measure current consumption of fuel pump → Chapter.