1984 Audi QuattroFACTORY OEM SERVICE PROCEDURE

Ignition System: Description

NOTE: Audi 4000S Quattro and 5000 Quattro use the Bosch-Hitachi Digital Timing Control system. Audi 5000 Turbo ignition is controlled by the computerized engine control system. See appropriate article in the COMPUTERIZED ENGINE CONTROL section under the ENGINE PERFORMANCE category.

The Bosch Hall Effect electronic ignition system consists of a breakerless Hall Effect distributor, a Hall (ignition) control unit, ignition coil, ignition switch, and battery.

Incorporated into the ignition system on Audi models is an idle stabilizer, a solid state control unit located between the Hall (ignition) control unit and the distributor's Hall generator.

The idle stabilizer replaces the distributor, sending signals to the ignition control unit when engine speeds fall below 940 RPM.

NOTE: On Audi 4000 (with 5-cylinder engines) and 5000 models, a Gray-colored impedance transformer may be installed in place of the idle stabilizer. Its purpose is to prevent interference and protect instruments from excessive voltage.

The Hall Effect distributor has conventional centrifugal and vacuum advance mechanisms. See Figure.

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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  • • The engine overheats, stalls repeatedly, or misfires under load.
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