Checking injectors (comparison measurement of injection quantity) — AUDI

Special tools and workshop equipment required

Quantity comparison measuring instrument V.A.G 1348
Adjusting device V.A.G 1348/1A
Measuring device V.A.G 1348/2B

Injector tester V.A.G 1349

Note:

Spray pattern of injectors with Viton seals cannot be tested.

Check spray pressure and for leaks

Remove upper part of intake manifold:

=> 5-cylinder Engine (2-valve), Mechanical Components; Repair group 15; Removing and installing cylinder head; Removing and installing upper part of intake manifold
5-cylinder Engine (2-valve), Mechanical Components
Removing and installing cylinder head
Removing and installing upper part of intake manifold

Unscrew bolts -arrows-.
Remove retaining plates.
Remove injectors from lower part of intake manifold and set aside.
Disconnect fuel line on injector to be checked.

Connect injector to V.A.G 1349.
Bleed line to injector with union nut open by operating lever on V.A.G 1349 several times.
Tighten union nut.
Bleed injector by operating lever on V.A.G 1349 rapidly 10...15 times.

Open cut-off valve.
Check spray pressure by operating lever slowly.
Specification: 3.7...4.8 bar

If specification is not attained:

Replace injector.

If specification is attained:

Carefully increase pressure up to just below opening pressure and wait.
No drip should emerge from injector within 2 minutes.

Checking idling speed injection tolerance

Connect remote control V.A.G 1348/3A with adapter cable V.A.G 1348/3-2 => Page
25-110
.
Screw fuel lines back onto injectors.
Insert all injectors into V.A.G 1348/2.

Note:

Ensure that fuel lines are routed free of kinks, if necessary remove from retaining clips.

Screw adjusting screw -1- and knurled nut -4- on V.A.G 1348/1A into upper end position and pull slide -2- upwards.
Position V.A.G 1348/1A on edge of air flow meter so that tip -3- points towards fuel distributor.
Push in slide -2- up to stop.
Hold baffle plate in rest position by hand.
Screw adjusting screw -1- in until magnetic base makes contact with securing bolts of baffle plate.

Turn knurled nut -2- 15 mm downwards.
Press switch on remote control for 20 seconds.
Compare fuel quantities of injectors with each other.
Maximum permissible deviation: 2.5 ml
on all injectors

Note:

Hold measuring device horizontal.

If deviation is greater:

Interchange injectors with greatest and smallest injection quantities.
Empty V.A.G 1348/2.
Repeat test.

If differing fuel quantity has migrated with injector:

Injector defective

If differing fuel quantity has remained at same cylinder:

Line to injector restricted or fuel distributor defective

Checking full throttle injection tolerance

Empty V.A.G 1348/2.

Turn knurled nut -2- 30 mm downwards.
Press switch on remote control for 20 seconds.
Compare fuel quantities of injectors with each other.
Maximum permissible deviation: 8.0 ml
on all injectors

Note:

Hold measuring device horizontal.