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.
1990 Audi 100 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Spark Plug Wires & Rotor
- Check coil wire resistance. If radio suppression wires are used, coil wire resistance reading should be 1200-2800 ohms. If suppression wires are not used, resistance reading should be zero ohm.
- Check resistance of spark plug wires. Resistance should be 4600-7400 ohms if radio suppression wires are used, otherwise resistance should be 600-1400 ohms. Check resistance of spark plug connectors. Resistance should be 4000-6000 ohms if radio suppression connectors are used, and 600-1400 ohms if they're not used.
- Check rotor and spark plug wire distributor cap connectors. Resistance of each connector should be 600-1400 ohms. Ensure rotor is marked R1.
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.