Measuring Injection Quantity

- switch US 4480/3 OFF
- remove fuel pump relay and jump socket with US 4480/3





- attach analyzer US 4480 to bumper and secure with chain

WARNING: Fire hazard. Do not smoke or have anything in area that can ignite fuel

- remove injectors from cylinder head with fuel lines connected
- check injector seals for damage or loose fit and replace as necessary
- check tightness of injector insert with 13 mm hex wrench
^ 20 Nm (14.7 ft lb)

If loose
- remove and clean threads
- reinstall inserts
- install injectors (with lines attached) into measuring device
- make sure fuel lines are not kinked or bent. If necessary, loosen fittings to properly locate fuel lines, then retighten
- remove rubber boot from intake air sensor





- turn and lift adjusting screw 1 and slide 2 into upper (full throttle) position on VW 1348/1
- place W 1348/1 centrally on edge of air flow sensor assembly
- pointer 3 faces to center of fuel distributor
- push adjusting slide 2 down onto stop
- turn seting screw 1 clockwise until magnetic end contacts air flow sensor plate retaining bolt
- switch ON adapter us 4480/3
- turn adjusting screw 1 counterclockwise until beginning of fuel injection is seen at one injector
- switch OFF us 4480/3 adapter and empty us 4480 analyzer into vehicle fuel tank

IDLE INJECTION QUANTITY, MEASURING
- lift adjusting slide 2 of VW 1348/1 to first stop (simulated idle)
- switch ON adapter us 4480/3 until fuel level on scale of one measuring glass reaches 20 ml fuel
- note injector spray pattern
^ must be even and cone chaped
^ all injectors should have same spray pattern

If NO
- briefly lift sensor plate up once, fully and repeat test
- compare amount of fuel for all injectors (keep measuring device level)
- note permissible difference between fuel quantity in all flasks
^ must not be more than max. 3.0 ml fuel

If fuel in flasks differs between high and low more than 3.0 ml
- interchange both injectors and repeat test

If difference of injected fuel did not change with interchanged injectors
- check it fuel line is pinched or fuel distributor is defective

If difference of injected fuel has changed with interchanged injectors
- replace injectors

FULL THROTTLE INJECTION QUANTITY, MEASURING
- empty measuring device US 4480. Reinstall injectors in measuring device
- lift adjusting slide 2 of VW 1348/1 to last stop (simulated full throttle)
- switch ON adapter US 4480/3 until fuel level on scale of one measuring glass reaches 80 ml fuel
- note injector spray pattern
^ must be even and cone shaped
^ all injectors should have same spray pattern

If NO
- briefly lift sensor plate up once, fully and repeat test
- compare amount of fuel for all injectors (keep measuring device level)
- permissible difference between fuel quantity in all flasks
- must be not more than 8.0 ml fuel

If fuel in flasks differs between high and low more than 8.0 ml
- interchange both injectors and repeat test
^ if difference of injected fuel did not change with interchanged Injectors, check if fuel line is pinched or fuel distributor is defective
^ if difference of injected fuel has changed with interchanged injectors, replace injectors

Immediately after measuring, test injectors for leaks
- set sensor plate in rest position
- switch ON adapter US 4480/3 for about 2 min.
^ injectors must not drip

If injector drips
- replace injector