1996 AUDI A4 fuel

24-48


Injection quantity, proper seal and spray
pattern of fuel injectors, checking

Special Tools and Equipment

VAG1348/3A
VAG1594A
VAG1598/31
VAG1602
VAS5051 with VAG5051/1
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24-49

Test requirement:

Fuel pressure OK, checking Page 24
-32
.

Test sequence

- Remove fuel distributor including fuel injectors
from intake manifold Page 24
-45
. Fuel lines
remain connected.

- Connect VAG1598/31 test box at wiring harness
to Engine Control Module (ECM), do not connect
ECM Page 24
-19
.

Checking Proper Seal

- Bridge terminals 1 and 65 at test box using wires
from VAG1594A adapter test kit.

- Switch ignition on.


Fuel Pump (FP) must run.

- Check proper seal of fuel injectors (visual
inspection). With Fuel Pump (FP) running, only 1
to 2 drops per minute may drip out per injector.

-
If fuel loss is greater, stop Fuel Pump (FP) from
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running (switch off ignition) and replace faulty
fuel injector Page 24
-45
.
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24-50

Checking Injection Quantity

- Insert fuel injector to be tested in a measuring
glass from VAG1602 injection quantity test
device.

- Connect one terminal of fuel injector to engine Ground (GND) using an
adapter cable and an alligator clip from VAG1594A connector test kit.
- Connect the second terminal of fuel injector to B+ using VAG1348/3A
remote control, VAG1348/3-2 adapter cable and assisting cable.
- Bridge terminals 1 and 65 at test box using wires from VAG1594A
adapter test kit.
- Bridge terminals 1 and 65 at test box using wires from VAG1594A
adapter test kit.
- Switch ignition on.

Fuel Pump (FP) must run.
- Activate VAG1348/3A remote control for 30 seconds.
- Perform measurement on all fuel injectors.
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24-51

- After all four fuel injectors have been activated,
place measuring glasses on an even surface.


Specified value for each fuel injector: 135
10 ml

- If measured value of one or more fuel injectors
is outside of specified range, switch Fuel Pump
(FP) off (switch ignition off) and replace faulty
fuel injector Page 24
-45
.

- If the measured values of all fuel injectors are
outside the specified range, check fuel pressure
Page 24
-32
.

Note:
Also check spray pattern when checking injection
quantity. Spray pattern must be the same for all
injectors

- Install fuel injectors together with fuel distributor
Page 24
-46
.
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24-52


Fuel Pump (FP) relay -J17- and activation,
checking

Special Tools and Equipment

VAG1526A
VAG1594A
VAG1598/31
VAS5051 with VAG5051/1
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24-53
Component location Overview of component
locations Page 24
-5
Voltage is supplied to the Fuel Pump (FP) and
several components of the injection system via
the Fuel Pump (FP) relay -J17-.
Engine must be turning for Fuel Pump (FP) relay
-J17- to close. This means that the relay does
not receive Ground (GND) (via ECM) until the
ECM recognizes RPM signals.

Test requirement:

Battery voltage at least 12.7 V

Function test of Fuel Pump (FP) relay

- Remove driver-side storage compartment.

Repair Manual, Body Interior, Repair Group
68


- Connect VAS5051 tester Page 01
-7 and
select vehicle system "01 - Engine electronics".
Ignition must remain switched on for this.

-
Initiate output Diagnostic Test Mode (DTM)
Page 01
-51
and activate Evaporative Emission
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24-54


A - If relay does not trigger:
B - If relay triggers, but Fuel Pump (FP) does not run:
Check voltage supply of Fuel Pump (FP) relay
Fuel Pump (FP) relay (at position 4 of central electronics in driver's
footwell, left) must trigger and Fuel Pump (FP) must run.
- Check voltage supply of Fuel Pump (FP) relay Page 24
-54
.
- Checking activation of Fuel Pump (FP) relay Page 24
-55
.
- Check voltage supply for Fuel Pump (FP) and components (via Fuel
Pump -FP- relay) Page 24
-57
.
- Remove Fuel Pump (FP) relay.

- Connect multimeter to terminal 17 of relay socket and Ground (GND)
for voltage measurement.

Specification: approx. battery voltage
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