Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1989 Audi 90 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Airflow Sensor Plate
- With engine off, upper edge of airflow sensor plate must be .118-.875" (1.9-3.0 mm) below edge of air cone. See Fig 1 .
- If sensor plate position is incorrect, adjust by bending wire clip located under sensor plate. Try to achieve the smaller setting of .118" (1.9 mm).CAUTION: DO NOT scratch venturi of airflow sensor or bend leaf spring.
- Airflow sensor plate free play is measured on the fuel distributor side of air plate. See Fig 2 . With ignition coil wire disconnected and grounded, crank engine for 10 seconds. Slightly lift airflow sensor plate until resistance is felt. Clearance should be .039-.118" (1.0-3.0 mm).
- If airflow sensor plate clearance is incorrect, adjust by turning control plunger stop screw. Loosen stop screw lock nut and turn screw. Turning stop screw clockwise increases clearance about .05" (1.3 mm) for each 1/4 turn. Recheck free play and idle speed.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.