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
Cold Crank Enrichment
- Using Adapter Cable (US 1112), connect Green test lead to OXS system test connector (Blue/Black wire). Connect Dwell Meter (VW 1367) to vehicle. Set the "%" button on dwell meter.
- Ensure engine is below 68°F (20°C). Unplug and ground high tension spark lead at coil. Crank engine and ensure duty cycle remains constant at 80%. If not, check coolant sensor. If sensor is okay replace ECU.
- If duty cycle reading is okay but cold start problems exist, check cold start valve and idle stabilization system.
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.