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
Idle Speed, Co Level & Ignition Timing
Ensure idle speed and ignition timing are set to specification. See appropriate IDLE SPEED & CO LEVEL SPECIFICATIONS and IGNITION TIMING tables. For adjustment procedures, see ADJUSTMENTS article.
4-CYLINDER IDLE SPEED & CO LEVEL SPECIFICATIONS
| Application | Idle RPM | CO Level % |
|---|---|---|
| All Models | 780-900 | .2-1.2 |
5-CYLINDER IDLE SPEED & CO LEVEL SPECIFICATIONS
| Application | Idle RPM | CO Level % | |||
|---|---|---|---|---|---|
| 2.2L (M/T) (1) | 750-850 | .3-1.2 | |||
| 2.3L | |||||
| Checking Value | 720-860 | .3-3.0 | |||
| Adjusting Value | 720-860 | .6-1.0 | |||
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4-CYLINDER IGNITION TIMING
| Application | Degrees BTDC @ RPM |
|---|---|
| Checking Value | 4-8 @ 780-900 |
| Adjusting Value | 5-7 @ 780-900 |
5-CYLINDER IGNITION TIMING
| Application | Degrees BTDC @ RPM | |
|---|---|---|
| 2.2L | ||
| Manual Transmission | TDC @ 750-850 | |
| Automatic Transmission | TDC @ 670-770 | |
| 2.3L | ||
| Checking Value | 13-17 @ 720-860 | |
| Adjusting Value | 14-16 @ 720-860 | |
Factory Service Tools
Use the Manual With the Right Hardware
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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.