Volkswagen Workshop Service and Repair Manuals

Checking delivery rate –  Remove seat bench (Golf Plus: rear right seat) → General body repairs, interior; Rep. Gr.72.

–  Remove cover -1- with fuel pump control unit -J538--2- from fuel delivery unit.

–  Pull 5-pin connector off fuel delivery unit flange.

–  Connect test instrument adapter/DSO (5-pin) -VAS 5565- to connector and fuel delivery unit. –  Connect remote control for V.A.G 1348 -V.A.G 1348/3A- to test instrument adapter/DSO (5-pin) -VAS 5565- and to battery positive (+).   Note This step serves only to have the fuel pump running when the engine is stopped. –  Remove filler cap from fuel tank filler neck.   WARNING The fuel supply line is pressurized! 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 supply line -2- and catch escaping fuel with a cloth.   Note Press in securing ring to release fuel lines.

–  Connect pressure tester -V.A.G 1318- with connector -V.A.G 1318/23- and adapter set -V.A.G 1318/17A- to fuel supply line –  Push hose adapter -V.A.G 1318/16- onto adapter -V.A.G 1318/11- of pressure tester and hold it in measuring container.   WARNING Danger of spray when shut-off tap is opened. Wear eye protection and protective clothing to avoid injuries and skin contact. Hold container before free connection of pressure tester. –  Open shut-off tap of pressure tester. The lever then points in direction of flow -A-. –  Operate remote control -V.A.G 1348/3A-. Then slowly close shut-off tap 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. –  The delivery rate of the fuel pump depends on the battery voltage. Therefore connect the multimeter -V.A.G 1715- with auxiliary cables from auxiliary measuring set -V.A.G 1594C- to the vehicle battery. –  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 (approx. 2 volts less than battery voltage). Example: During the test a voltage of 12.5 volts is measured at the battery. As the voltage at the pump is approx. 2 volts less than the battery voltage, this will equate to a minimum delivery rate of approx. 580cm3/30 seconds. If the minimum delivery rate is not attained: –  Check fuel lines for possible restrictions (kinks) or blockages. If no fault is found:   WARNING The fuel supply line is pressurized! 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 supply hose -1- off fuel filter inlet.

Engine code AXW:

Engine codes BLX, BLY, BLR, BVX, BVY, BVZ: –  Connect pressure tester -V.A.G 1318- with adapter set -V.A.G 1318/17A- to hose. –  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 for dirt in filter strainer. Only if still no fault has been detected: –  Renew fuel delivery unit. If delivery rate has been attained, but nevertheless you suspect a fuel supply system fault (e.g. intermittent failure of fuel supply system): –  Measure current consumption of fuel pump → Chapter.