Fuel Pump: Testing and Inspection

Delivery Rate, Checking

Test conditions
- Voltage supply OK.
- VAG 1348/3A Remote control connected

WARNING!
Fire Hazard. Do NOT have anything in the area that can ignite fuel.

Test sequence
- Remove filler cap from fuel filler neck.

WARNING!
Fuel supply lines are under pressure! Before removing line from hose connection, wrap a cloth around the connection and then release pressure by carefully pulling hose off connection.


Vehicles > 07.96







- Pull fuel supply line off tee -2-

Vehicles 08.96 >







- Pull fuel supply line off connection -1-.

Continued for all vehicles

- Connect pressure gauge VAG 1318 to fuel supply line -1- using 1318/10 adapter
- Push VAG 1318/1 hose onto VAG 1318/11 adapter on pressure gauge and hold hose over a measuring container.
- Open the pressure gauge cut-off tap. The lever then points in the through flow direction -A-.
- Operate remote control VAG 1348/3A. While doing this slowly close shut-off, until gauge shows 3 bar, from this point on do not alter the position of the shut-off
- Empty the measuring container.
- Operate remote control for 30 seconds.







- Compare the quantity of fuel delivered with the specification.

*) Minimum delivery cubic cm/30 seconds
**) Voltage at fuel pump with engine stationary and pump running (approx. 2 Volts less than battery voltage).

Example:
During test, 12.5 Volts is measured at battery. Pump voltage is approx. 2 Volts less than the battery equating to a minimum delivery of 500 cc's in 30 seconds

If minimum delivery rate not obtained:
- Check the fuel lines for possible restrictions, kinks or blockage.
- Replace fuel filter if blocked.
- Replace fuel pump if faulty.

If delivery rate has been obtained but you still suspect a fuel supply system malfunction, e.g. intermittent fuel supply
- Check the amperage draw of the fuel pump as follows:
- Reconnect all disconnected fuel lines.







- Connect Fluke 83 multimeter to the red/white wire from wiring harness using the amperage adaptor
- Start engine and let idle
- Measure fuel pump amperage draw.
- Specification: max. 8 amps

NOTE: If the fuel system malfunction is intermittent, you can perform the check during a test drive, using a 2nd person.

If amperage draw is exceeded:
- Replace fuel delivery unit.