SEAT Workshop Service and Repair Manuals

Fuel pump delivery: checking

Special tools and workshop equipment required

t	Pressure tester -VAG 1318-

t	Adaptor -VAG 1318/1-

t	Adaptor -VAG 1318/11-

t	Adaptor -VAG 1318/17-

t	Adaptor -VAG 1318/23-

t	Remote control -VAG 1348/3A-

Special tools and workshop equipment required

t  Measuring tool set -VAG 1594C-

t  Multimeter -VAG 1715- Test sequence l  The voltage supply for the fuel pump OK l  Remote control -VAG 1348/3A- is connected l  Fuel tank: at least 1/4 full. l  Fuel system pressure and residual pressure OK → Chapter Checking cycle

–  Remove fuel supply pipe -1-, pressing in locking pins.   WARNING Fuel system is under pressure! Before opening the system place a cloth around the connection. Then release pressure by carefully loosening the connection.

–  Connect fuel supply pipe to pressure tester -VAG 1318-, using adapter -VAG 1318/17- and adapter -VAG 1318/23-. –  Connect adapter -VAG 1318/1- to adapter -VAG 1318/11- of pressure gauge and place its end in measuring container. –  Open cut-off tap on pressure gauge. The lever then points in throughflow direction -A-. –  Operate remote control -VAG 1348/3A- and slowly close shut-off tap, until pressure gauge shows 3 bar. –  From here on, do not change position of shut-off tap. –  Empty measuring container. –  The quantity of fuel delivered by the fuel pump is dependent upon battery voltage. Therefore, the multimeter must be connected to the battery using the measuring tool set -VAG 1594C-. –  Operate remote control -VAG 1348/3A- for 30 seconds and measure battery voltage

–  Check delivery range attained with specific value. –  Press switch on remote control for approx. 15 seconds. *) Minimum flow cm3/30s. **) Voltage in fuel pump with engine off and the pump working (approx. 2 volts less than battery voltage). Readout example: During the test, the battery voltage is measured at 12.5 volts. As the voltage at the pump is approx. 2 volts less than the battery voltage then this will equate to a minimum delivery of 200 c.c./30s If the minimum delivery rate is not attained: –  Check the fuel pipes to the filter for possible restrictions (kinks) or blockages. If fuel pipes are OK: –  Check delivery range before filter. –  Remove fuel supply pipe -1- from fuel filter entrance, pressing locking pin.   WARNING Fuel system is under pressure! Before opening the system place a cloth around the connection. Then release pressure by carefully loosening the connection. –  Connect fuel supply pipe to pressure tester -VAG 1318-, using adapter -VAG 1318/17-. –  Connect adapter -VAG 1318/11-and adapter -VAG 1318/1- to pressure gauge and place adapter end in a measuring container. –  Open cut-off tap on pressure gauge. The lever then points in the throughflow direction -A-. –  Operate remote control -VAG 1348/3A- and slowly close shut-off tap, until pressure gauge shows approx. 3 bar. –  From here on, do not change position of shut-off tap. –  Empty measuring container. –  The quantity of fuel delivered by the fuel pump is dependent upon battery voltage. Therefore, the multimeter must be connected to the battery using the measuring tool set -VAG 1594C-. –  Operate remote control -VAG 1348/3A- for 30 seconds and measure battery voltage –  Repeat delivery rate check. If the minimum delivery rate is now attained: –  Replace fuel filter. If the minimum delivery rate is not again attained: –  Remove the fuel delivery unit and check the strainer filter for soiling. Only when up to now no fault has been detected: –  Replace fuel delivery unit → Chapter. If the delivery rate has been attained but nevertheless you suspect a fuel supply system fault (e.g. intermittent failure of fuel supply system): –  Check the current draw of the fuel pump as follows: –  Reconnect all disconnected fuel pipes.

–  Using the current pincers, connect the Multimeter -VAG 1715- to one of the supply cables of the fuel pump (exterior contacts of the flange connector). –  Start engine and run at idling speed. –  Measure the current consumption of the fuel pump. Specification: 8 amps maximum   Note If there is a temporary fuel system fault, the check can also be carried out during a test drive, with the help of a second person. If the current draw is exceeded: –  Replace fuel delivery unit → Chapter.