Checking injectors (injection quantity comparison measurement) — AUDI

Special tools and workshop equipment required

Quantity comparison tester V.A.G 1348
Adjusting tool 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 checked.

Checking spray pressure and freedom from leaks

Remove upper part of intake manifold.

=> 5-cyl. Engine (2-valve), Mechanics; Repair Group 15; Removing and installing cylinder head; Removing and installing upper part of intake manifold
5-cyl. Engine (2-valve), Mechanics
Removing and installing cylinder head
Removing and installing upper part of intake manifold

Screw out bolts -arrows-.
Detach retainers.
Pull injectors out of lower part of intake manifold and lay them aside.
Disconnect fuel pipe at injector to be checked.

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

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

If reading does not match specification:

Replace injector.

If reading matches specification:

Carefully increase pressure up to just less than opening pressure and then wait.
Injector must not dribble within 2 minutes

Checking idle injection tolerance

Connect up remote control V.A.G 1348/3A with adapter lead V.A.G 1348/3-2 => Page
25-109
.
Re-connect fuel pipes to injectors.
Insert all injectors in V.A.G 1348/2.

Note:

Make sure fuel pipes are not kinked; remove from retaining clips if necessary.

Screw adjusting screw -1- and knurled nut -4- at V.A.G 1348/1A into upper end position and pull slide -2- upwards.
Position V.A.G 1348/1A on rim of air-flow meter such that tip -3- points in direction of fuel distributor.
Push in slide -2- as far as it will go.
Hold sensor plate manually in rest position.
Screw in adjusting screw -1- until magnetic base makes contact with securing bolt of sensor plate.

Screw down knurled nut -2- by 15 mm.
Press switch on remote control for 20 seconds.
Compare fuel quantities of injectors.
Permissible difference: max. 2.5 ml
for all injectors

Note:

Hold measuring device horizontal.

If difference is greater:

Interchange injectors with highest and lowest injection quantity.
Drain V.A.G 1348/2.
Repeat test.

If difference in fuel quantity accompanies injector:

Injector defective

If difference in fuel quantity is still found at same cylinder:

Pipe to injector constricted or fuel distributor defective

Checking full throttle injection tolerance

Drain V.A.G 1348/2.

Screw down knurled nut -2- by 30 mm.
Press switch on remote control for 20 seconds.
Compare fuel quantities of injectors.
Permissible difference: max. 8.0 ml
for all injectors

Note:

Hold measuring device horizontal.