Volkswagen Golf / Golf GTI / Jetta. Manual - part 77

20-31

 

  

  

Checking delivery rate  

  

  

Test conditions  

  

  

 Voltage supply OK. 

  

  

 Remote control VAG 1348/3A 

connected. 

  

  

Test sequence  

  

  

-  Remove filler cap from fuel tank 

filler neck. 

    

Note:  

Press buttons on hose couplings to 
do so. 

WARNING!

 

Fuel supply lines are under 
pressure! Before removing from 
hose connections wrap a cloth 
around the connection. Then 
release pressure by carefully 
pulling hose off connection.

 

-  Disconnect supply hose -3- (with 

white marking) and collect fuel 
that may leak out with a cloth. 

Components of fuel supply system, servicing

20-32

 

    

The quantity of fuel delivered by the 
fuel pump depends on the battery 
voltage.  

-  Connect pressure gauge VAG 

1318 to fuel supply pipe using 
adapter VAG 1318/23 and VAG 
1318/17. 

-  Push hose adapter VAG 1318/16 

onto adapter VAG 1318/11 on 
pressure gauge and hold hose in 
a measuring container. 

-  Open shut-off tap on pressure 

gauge. Lever then points in flow 
direction -A-. 

-  Operate remote control VAG 

1348/3A. Close shut-off tap 
slowly, until pressure gauge 
shows 3 bar. From now on do not 
alter setting of shut-off tap. 

-  Empty measuring container. 

-  Connect multimeter to vehicle 

battery using adapter cables from 
VAG 1594 A. 

-  Operate remote control for 30 

seconds and measure battery 
voltage. 

Components of fuel supply system, servicing

20-33

 

    

*)

 Minimum delivery cm

3

/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 12.2 
volts is measured at the battery. As 
the voltage at the pump is approx. 2 
volts less than the battery voltage, 
the result is a minimum delivery of 
200 cm

3

/30 seconds.  

If the minimum delivery rate is not 
attained:  

-  Compare quantity of fuel 

delivered with nominal value. 

-  Check fuel pipes for possible 

restrictions (kinks) or blockages. 

    

Note:  

Press buttons on hose couplings to 
disconnect. 

-  Disconnect fuel line -1- from input 

side of fuel filter. 

-  Connect pressure gauge VAG 

1318 to hose using adapter 
1318/17. 

-  Repeat delivery rate test. 

Components of fuel supply system, servicing

20-34

 

  

   If the minimum delivery rate is now attained:  

  

  

-  Replace fuel filter. 

  

   If the minimum delivery rate is again not 

attained:  

  

  

-  Remove fuel delivery unit and check strainer 

filter for soiling. 

  

   Only if no faults have been detected up to now:  

  

  

-  Fuel pump faulty, replace fuel delivery unit 

 

Page 20-15

 , Removing and installing fuel 

delivery unit. 

  

   If the delivery rate has been attained but a fuel 

supply system fault is still suspected (e.g. 
intermittent failure of fuel supply system):  

  

  

-  Check current draw of fuel pump as follows: 

  

  

-  Reconnect all disconnected fuel lines. 

Components of fuel supply system, servicing