California

Check and adjust the basic engine settings in the following order:

1. Ignition timing
2. CO content
3. Idle speed
4. Final check of specifications

TEST AND ADJUSTMENT CONDITIONS

NOTE: Check, correct and erase any stored fault codes before continuing with testing. Results can be affected due to the Digifant I control units adaptive circuits.

1. Engine oil temperature must be at least 176° F (80° C) and radiator cooling fan has operated at least once.
2. All electrical consumers switched "OFF" (radiator cooling fan must not be running during checking or adjusting).
3. A/C switched "OFF".
4. Throttle valve potentiometer is functioning properly.
5. Idle stabilization system operating properly, the valve must vibrate and hum while the ignition is "ON".
6. The exhaust system must be free of leaks.
7. There must be no engine vacuum leaks.
8. The oxygen sensor must be operating properly.

TEST AND ADJUSTMENT SET-UP

1. Turn ignition switch "OFF".
2. Connect VW 1367 engine tester (or suitable timing light and tach.)
3. Connect an EPA approved CO tester to the CO tap tube using VW special tool #6006-0019 high temperature silicone connecting hose, (or equivalent).

NOTE: Non-approved connecting hoses may dramatically alter your readings.

IGNITION TIMING

1. START the engine and let idle.

Coolant Temperature Sensor Connector:

2. Disconnect the harness connector from the blue coolant temperature sensor.

Ignition Timing Mark:

3. Increase the engine speed to 2300 ± 50 rpm and check the ignition timing. Specifications are:

Checking: 4° to 8° BTDC
Adjusting: 6° ± 1° BTDC

4. If adjustment is necessary, loosen the distributor clamp bolt and rotate the distributor until specification is correct.
5. Tighten the distributor clamp bolt to:

18 ft.lb. (25 Nm)

6. Reconnect the blue coolant temperature sensor. Fault code 2312 is generated whenever the coolant temperature sensor is disconnected while engine is running. Refer to ON-BOARD DIAGNOSIS for reset procedures.

IDLE SPEED AND CO CONTENT

1. START engine and let idle.
2. Idle speed and CO content must be:

750 to 850 RPM
0.3% to 1.2% CO

NOTE: DO NOT attempt to adjust the idle speed using the idle air bypass screw. Idle speed is computer controlled.

3. Record the CO value before adjustment.
4. If not within specification, use the following procedures.
5. Turn ignition switch "OFF"

Crankcase Ventilation Hose:

6. Disconnect the crankcase ventilation hose from the emission control valve and plug the hose.
7. START the engine and let idle

Coolant Temperature Sensor Connector:

8. Disconnect the blue coolant temperature sensor harness connector.
9. Reconnect harness connector after 1 minute.

NOTE: Fan must not be running while reconnecting coolant temperature sensor.

10. Reconnect crankcase ventilation hose.
11. Fault code 2312 is generated whenever the coolant temperature sensor is disconnected while engine is running. Refer to ON-BOARD DIAGNOSIS for reset procedures.
12. Recheck idle speed and CO content.

Idle Speed 750 to 850 RPM
CO Content 0.3% to 1.2%

FINAL CHECK

1. Disconnect the test equipment, check all hose and electrical connections and reinstall CO tap cap.
2. Road test vehicle for 10 minutes. Coolant temperature must be over 176°F (80°C) for at least 3 minutes before testing. Try to duplicate original complaint.
3. During test drive, perform the following operations:
a. With engine speed over 4600 RPM, push gas pedal to full down position briefly.
b. While driving at 30 Mph (50 Km/h) in 4th gear, accelerate with gas pedal pushed halfway down for about 4 seconds.
4. After road test check for fault codes.
5. If only the idle speed is NOT OK:
a. Check the throttle valve potentiometer and wiring.
b. Check the idle stabilization system.
6. If only the idle CO% is NOT OK:
a. Check the oxygen sensor system.
7. If the idle speed and idle CO% are NOT OK:
a. Check the coolant temperature sensor and wiring.