seat Workshop Repair Guides

SEAT Workshop Service and Repair Manuals

ABOUT US
Checking fuel pump non-return valve > < Checking function and voltage supply

Leon Mk2

Checking delivery rate
Checking delivery rate
Test conditions
l  The voltage supply for the fuel pump OK.
l  Remote control -V.A.G 1348/3A- connected.
Test sequence
–  Remove filler cap from fuel tank filler neck.
  Caution
The fuel system is pressurised. Before opening the system, place a cloth around the place for the coupling. Next, remove the pressure by carefully dismounting the flexible pipe.
   
–  Extract the supply piping -1- and mop up the fuel that leaks with a cloth.
  Note!
To do so, press down the keys on the couplings for the flexible tubes.
  E10-0018
–  Connect pressure gauge -V.A.G 1318- with Adapter -V.A.G 1318/23- and Adapter -V.A.G 1318/17- to the fuel supply pipe.
–  Push the hose -V.A.G 1318/1- onto the adapter -V.A.G 1318/11- on the pressure gauge and hold hose in a measuring container.
–  Open the pressure gauge shut-off tap. The lever then points in the throughflow direction -A-.
–  Operate remote control -V.A.G 1348/3A- and slowly close cut-off tap, until pressure gauge shows 3 bar. From this point on do not move position of cut-off tap.
–  Empty the measuring container.
–  The fuel pump delivery range is dependent upon battery voltage. Therefore connect the multimeter with adapter cables from -V.A.G 1594A- or -V.A.G 1594C- to the vehicle battery.
–  Operate remote control for 30 seconds and measure battery voltage.
  E20-0030
–  Compare the quantity of fuel delivered with specification.
*) Minimum delivery cm3/30 seconds.
**) Voltage at fuel pump with engine stationary and pump running (approx. 2 volts less than battery voltage).
Example:
During the check, the voltage measured in the battery was 12.5 volts. Since there are 2 volts less in the pump than in the battery, the minimum resulting flow rate is 540 c.c./30 s.
If the minimum delivery rate is now attained:
–  Check the fuel pipes for possible restrictions (kinks) or blockages.
–  Pull supply hose -1- off inlet to fuel filter.
  N20-0134
–  Connect the pressure gauge -V.A.G 1318- with adapter /17 on hose.
–  Repeat delivery rate check.
If the minimum delivery rate is now attained:
–  Replace the fuel filter.
If the minimum flow rate is not reached again:
–  Dismount the fuel supply unit and check the filter for dirt.
Only when up to now no fault has been detected:
–  Replace the fuel supply unit.
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.
  N20-0242
–  Using the current reader clamp, couple the multimeter -V.A.G 1715- to one of the power supply cables for the fuel pump (outer contacts for the clamp connector).
–  Start the engine and run at idling speed.
–  Measure the current draw of the fuel pump.
Specification: max. 8 amps.
  Note!
If it involves a temporary problem for the fuel system, the check may also be made during a test run, in which case it is necessary that another person should help.
If the current draw is exceeded:
–  Fuel pump defective, renew fuel delivery unit → Chapter.
  N20-0061

Checking fuel pump non-return valve > < Checking function and voltage supply