Tune-Up - 4-cyl Audi 80 B3

ENGINE IDENTIFICATION

Engine number is stamped on left side of engine block, below thermostat housing.

ENGINE CODE

ENGINE COMPRESSION

Check compression with engine warm, all spark plugs removed and throttle wide open. Crank engine at least 6 strokes per cylinder.

Note. Connect coil high tension wire to ground before cranking engine for compression test.

COMPRESSION SPECIFICATIONS

HIGH TENSION WIRE RESISTANCE

HIGH TENSION WIRE RESISTANCE (1)

SPARK PLUG SPECIFICATIONS

SPARK PLUG TYPE

SPARK PLUG SPECIFICATIONS

VALVE CLEARANCE

Engine is equipped with hydraulic valve lifters. No adjustment is necessary.

Note. If lifters are replaced, DO NOT start engine for 30 minutes as valves may hit pistons. Lifters must be allowed to bleed down before starting engine.

VALVE ARRANGEMENT

1. E-I-E-I-I-E-I-E (Front-to-rear).

Distributor

Engine is equipped with CIS-Motronic computerized engine control system. Ignition timing is controlled electronically once base ignition timing is set.

Firing Order & Distributor Rotation. Scheme 1

IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C)

IGNITION TIMING

Ignition timing, idle speed, and idle mixture are closely interelated and MUST be checked/adjusted together. See IDLE SPEED in this article.

IGNITION TIMING (DEGREES BTDC @ RPM)

Scheme 2

Entering Diagnostic Mode

1. Ensure that fuses No. 13, 24 and 28 are okay. Check that ground connection to intake manifold is clean and tight, Start and warm engine to normal operating temperature.
2. Increase engine speed to 3000 RPM, and then allow engine to idle for at least 2 minutes. On California vehicles, check that fuse No. 12 and malfunction indicator light are okay.
3. Connect Light Emitting Diode (LED) Tester (US 1115) to diagnostic connector and battery positive terminal. Turn ignition switch on, but DO NOT crank engine.
4. Insert fuse into fuel pump relay for at least 5 seconds, and then remove fuse. Lights on LED tester must start flashing. Count flash impulses and record. Each fault code consists of 4 digits, with 2.5 pause betweem each digit.
5. Switch to next test step by inserting fuse in fuel pump relay once again. Repeat procedure until end of self test code "0 0 0 0" is obtained. If fault codes are stored, faults in engine control system MUST be repaired.

Exiting Diagnostic Mode

1. To erase permanent fault code memory, turn ignition off. Insert fuse in fuel pump relay. Turn ignition on, LED tester must light up. Remove fuse after 4 seconds. Tester light must go out, and then begin displaying end of self test code "0 0 0 0".
2. Insert fuse in fuel pump relay for at least 5 seconds, and then remove. If tester lights up and stays on, permanent fault memory has been successfully erased. Erase secondary fault memory by starting engine.

Note. Fault codes of CIS-Motronic computerized engine control system MUST be checked before checking engine settings. If NO fault codes are stored, ignition timing, idle speed, and idle mixture may be checked/adjusted. Idle speed is electronically controlled and is NOT adjustable.

Scheme 3

1. Ensure engine is at normal operating temperature. Check that all electrical accessories and cooling fan are off. Increase engine speed to 3000 RPM, and then allow engine to idle for at least 2 minutes. Turn ignition off.
2. Using Test Adapter (VW 1363/3), connect CO tester to measuring tube. Connect Multimeter (US 1119) with Test Adapter (VW 1315A/1) to differential pressure regulator. (Scheme 3)
3. Turn ignition on. Control current must be positive. If not, reverse test probes. Remove crankcase housing breather hose and vent to atmosphere. Remove sealing cap from top of charcoal canister.
4. Connect timing light and check ignition timing. If necessary, remove tamper proof seal covering distributor clamp bolt and adjust ignition timing. After adjusting ignition timing, tigthen bolt and install a new tamper proof seal.
5. Check idle speed. If incorrect, check air intake system for leaks. If necessary, check/adjust airflow sensor potentiometer. If idle speed is correct, turn A/C system on (if equipped). Idle speed must increase by 70 RPM. If not, check CIS-Motronic computerized engine control system.
6. Check CO content by reading milliamp (mA) output on multimeter. Reading must fluctuate between zero and 5 milliamps. If reading is incorrect or it does not fluctuate, check oxygen sensor control system.
7. Read CO value on CO tester. Reading must be.2-1.2% by volume. If CO content is outside range, adjust idle mixture. Turn ignition off and remove rubber boot from mixture control unit.
8. Center punch hole in CO adjusting hole and drill a 3/32" hole to a depth of 5/32". DO NOT drill completely through as adjustment screw will be damaged. Install a 1/8" sheet metal screw and remove plug using pliers.
9. Install rubber boot on mixture control unit. Start and run engine at idle. Using Adjustment Wrench (P 377), turn adjustment screw clockwise or counterclockwise to adjust CO reading. (Scheme 4) Install new plug in mixture control unit.

Note. DO NOT push down on adjustment screw and do not accelerate engine with adjustment wrench in place. Remove wrench after each adjustment and accelerate engine briefly before measuring CO reading.

Scheme 4

IDLE MIXTURE & CO LEVEL

Ignition timing, idle speed, and idle mixture are closely interelated and MUST be checked/adjsted together. See IDLE SPEED in this article. Mixture adjustment is not a normal tune-up procedure on fuel injected engines.

IDLE SPEED & CO LEVEL SPECIFICATIONS

Fuel Injection

Engine is equipped with CIS-Motronic computerized engine control system. Idle speed may be checked, but is not adjustable. System includes a self-diagnostic feature to detect and store malfunctions that occur during vehicle operation.

FUEL PUMP PERFORMANCE

BATTERY

BATTERY SPECIFICATIONS

BELT ADJUSTMENT

BELT ADJUSTMENT (1)

SERVICE INTERVALS

REPLACEMENT INTERVALS

CAPACITIES

FLUID CAPACITIES

See also:
• IDLE SPEED