ADJUSTING/CHECKING ENGINE IDLE SPEED/CO LEVEL
Requirements:
Air filter cartridge in perfect condition.
Engine at operating temperature (oil temperature
at least 60°C/140°F).
Ignition timing and valve play okay.
All electric equipment switched off.
CO tester warm and calibrated.
Switch off the exhaust gas extraction system
during tests to avoid incorrect values.

A) Engine Idle Speed:
Detach hose from collector to carbon filter and
don´t plug openings.
Detach air hose from air pump and insert plug.

Adjust idle speed¹) with screw (1).
Turning screw (1) clockwise lowers idle speed.
Engine must run as smooth as possible for adjusting.


¹) See microfilmed Specifications

B) CO Level:
For CO level adjustments note plug (3) on
L-Jetronic control unit for high altitude correction.
If car is operating in a high altitude area, plug (3)
must be connected.

CO level at idle speed¹) must be checked.


¹) See microfilmed Specifications

CO level at idle speed: 1.5 to 3.0% by volume.
CO Level Too Low:
a) Leak in intake system after air flow sensor.
b) Auxiliary air valve defective 11 61 090.
c) Fuel pressure regulator defective 13 51 200.
d) Fuel filter partially clogged 13 32 051.
e) Check fuel pump pressure 13 31 029.
f) EGR valve leaks 11 71 501.
g) Exchange control unit to test 13 61 000.
h) Check fuel injection function 13 60 009.
CO Level Too High:
a) Oil dipstick not tight enough in guide tube.
b) Too much oil in crankcase.
c) Intake and exhaust valves leak.
d) Exchange air flow sensor to test 13 62 000.
e) Cold start aid won´t turn off 13 64 009.
f) Check fuel injection function 13 60 009.
g) Fuel injectors leak 13 64 501.
Positions a) ... h) not cause:
Remove end cap (3) with an angled scribe or
similar tool.
Adjust CO level to correct value by using Special
Tool 13 1 060 on air control screw in the air
flow sensor.


11 61 090
13 51 200
13 32 051
13 31 029

Version with Oxygen Sensor:
Requirements for all tests:
Engine at operating temperature, i.e. oil temperature
at least 60°C (140°F).
Ignition timing and valve play okay.
All electric equipment switched off.
CO tester warm and calibrated.
A) Engine Idle Speed:
Connect BMW service test unit according to
operating instructions.
Adjust idle speed¹) with screw (1).


¹) See microfilmed Specifications

B) CO Level:
Pull off hose from collector to carbon filter.

Unscrew cap nut from connection for exhaust
gas probe and screw on probe 13 0 070.
Connect CO tester.

CO level at idle speed should be between 0.2 and
0.8 % by volume.
CO Level Too Low:
1.) Leak in intake system after air flow sensor.
Check intake pipes, intake necks, hoses and
connections for leaks.
2.) Leak in crankcase.
Check valve cover gaskets, oil pan, oil dipstick
and vent line for leaks.

The idle speed CO level should not change when
pulling plug off of oxygen sensor.

Adjusting CO Level:
Remove end cap (3) with an angled screwdriver
or similar tool.
Adjust CO level to correct value by applying
Special Tool 13 1 060 on air screw in the air
flow sensor.

From 1981 Models:
Remove air flow sensor to remove the antitamper
lock.
Drill off anti-tamper lock with Special Tool
13 1 092.

Screw Special Tool 13 1 094 in the anti-tamper
lock.
Knock tool and anti-tamper lock out of air
flow sensor with impact tool (1).

Install air flow sensor.
Adjust engine idle speed and CO level.
After completion of adjustments remove air
flow sensor again and install a new anti-tamper
lock (1).

Vehicles after change point in 1982
ADJUSTING ENGINE IDLE SPEED / CO TEST
Requirements for All Adjustments:
Engine at operating temperature, i.e. oil
temperature at least 60°C (140°F).
Ignition timing and valve clearance correct.
All electric equipment switched off.
BMW service test unit connected to
operating instructions.

1) Engine Idle Speed:
Check engine idle speed**.
If specified valuw is not reached, check idle
control valve (1) and idle speed regulation
control unit (2), replacing if necessary.
Note:
There is no adjusting screw for idle speed
regulation.


** See Nominal Value Microfilm

2) CO Test:
Pull off hose (1) on solenoid (2).
Do not insert plugs in open connections.

Unscrew bolts (1).
Connect Special Tool 13 0 090 on exhaust
manifold with adapter 13 0 100.
Check idle speed CO level**.


** See Nominal Value Microfilm

Pull off oxygen sensor plug.

Remove air cleaner with air flow sensor.
Drill hole in anti-tamper lock with Special Tool
13 1 092.

Screw Special Tool 13 1 094 in anti-tamper
lock.
Knock special tool and anti-tamper lock out
of air flow sensor with impact (1).
Install air cleaner with air flow sensor.
Run engine at idle speed.

Adjust CO to specified value** with Special
Tool 13 1 100.
Connect oxygen sensor.
Remove CO tester.


** See Nominal Value Microfilm

Remove air cleaner with air flow sensor.
Insert new anti-tamper lock (1) in air flow
sensor.
Install air cleaner with air flow sensor.

Connect oxygen sensor plug.