Checking idling speed, CO content and ignition point — AUDI

Special tools and workshop equipment required

V.A.G 1315A/1
V.A.G 1318/3
V.A.G 1526 A
V.A.G 1594 A
V.A.G 1767 or V.A.G 1367 with V.A.G 1367/8
V.A.G 1788
VAS 5051 with VAS 5051/1 and VAS 5051/2

or

V.A.G 1551 with V.A.G 1551/1

Notes:

The idling speed cannot be adjusted.
The idling speed is tested during the basic setting of the engine.

Test requirements:

No leaks in exhaust system
Coolant temperature at least 85 oC.
Electrical consumers switched off (radiator fan must not run during the test)
Air conditioner switched off.
Accelerator cable correctly adjusted

=> Fuel Supply System - Petrol Engines; Repair Group 20; Servicing accelerator mechanism; Adjusting throttle cable
Fuel Supply System - Petrol Engines
Servicing accelerator mechanism
Adjusting throttle cable

Pressure gauge not connected.
Lambda control OK
In case injection lines were slackened or replaced: Rev engine several times to 3000 rpm and let it run at idling speed for at least 2 minutes.

Connecting test equipment

Connect up vehicle diagnosis, measurement and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "Address word" 01 => Page
01-2
.
For this purpose, the engine must be running at idle speed
Interrogate fault memory => Page
01-9
. The fault memory must be clear. If necessary, rectify any faults and erase the fault memory. Switch off the engine, then start up again. Take vehicle for a test drive and interrogate the fault memory again to make sure it is clear.

Connect exhaust fume tester V.A.G 1788.

=> Operating instructions

Insert measuring probe into exhaust pipe.
Connect ignition tester V.A.G 1767 (or V.A.G 1367) with ignition switched off:

=> Operating instructions

Notes:

The TDC sender of ignition tester V.A.G 1367 must be inserted into the gearbox housing as far as the stop.
The ignition timing is indicated directly on V.A.G 1767 (or V.A.G 1367). It is not necessary to use a strobe light aimed at the timing notches.
If the trigger pliers are not sufficiently opened (e.g. by pulling too strongly on the spiral wire) error messages can be displayed on ignition tester V.A.G 1767.

System in basic setting 0
⇒
1
2
3
4
5
6
7
8
9
10
Initiate basic setting, display group 000=>Page
01-39
.
Check display in display zone 9.
Specification: 5

If the specification is not obtained:

Check idling switch -F60
=> Page
25-39
.

If the specification is obtained:

Read off the ignition point on the ignition tester V.A.G 1767 (or V.A.G 1367).
Test value 4 ... 8o: Before TDC.

Note:

If the ignition timing displayed is not within the tolerance range, you first of all have to set the ignition timing before testing idling speed so long as the system is still in "Basic setting 1".

Set the ignition timing point by turning the ignition distributor on.

Read off the idling speed on the ignition tester V.A.G 1767 (or V.A.G 1367).
Specification: 800 ... 1000/min 1)

Read CO content at exhaust fume tester.
Specification: 0.2 ... 1.2 Vol. % 1)

1)
Current values:

=> "Exhaust emission test" binder

If the specified values are attained:

To quit the basic setting, press the ⇒key.

Rapid data transfer HELP
Select function XX
When adjacent display appears:

Enter "06" for "End output" function and confirm entry with Q key.

If the CO value is outside the tolerance:

Switch ignition off.
Pull bleeder hose -1- off crank case-bleeder pipe -2-.
The connecting piece -3- must remain in the bleeder tube with calibrated boring.

Pull crank case bleeder tube out of connecting hose -4- so that only fresh air is being taken in.

Pull off connector of pressure regulator.

Switch multimeter to measuring range 200 mA and connect with measuring line V.A.G 1315A/1 between pressure regulator -1- and connector of pressure regulator -arrows-.
Switch the ignition on.
The pressure regulator current must be in positive range 90 ... 110 mA.

If the control current is in negative range:

Exchange connections at V.A.G 1315 A/1.
Start engine and run at idling speed.
System in basic setting 0
⇒
1
2
3
4
5
6
7
8
9
10
Initiate basic setting, display group 000=>Page
01-39
.

Set control current at adjusting bolt -2- with V.A.G 1318/3.
Setting: 2.5 ± 2.5 mA (fluctuating)

Note:

If control current does not fluctuate check lambda probe -G39 and lambda control => Page
25-110
.
When adjusting control current do not press adjusting key, do not accelerate with adjusting key inserted.
Remove adjusting key after each adjustment procedure and accelerate briefly before the control current can be read at idling speed.

To quit the basic setting, press the ⇒key.
Interrogate fault memory and erase it => page
01-9
.

If the idling speed is too high or too low and there are no faults recorded in the fault memory, carry out the following tests marked with a dot:

Test idling switch =>page
25-38
.
Check vacuum connections (unmetered air) => Page
25-130
.
Test for leaks (unmetered air) in intake air system => Page
25-56
.
Perform final control diagnosis => Page
01-34
.