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.
1994 Audi S4FACTORY OEM SERVICE PROCEDURE
Fuel Injectors Checking
NOTE:
When substituting fuel injectors, use only original equipment fuel injectors, designed for 5-cylinder Multiport Fuel Injection.
- Initiate Output Diagnostic Test Mode (DTM) using (VAG 1551). See OUTPUT DIAGNOSTIC TEST MODE (DTM) in SELF-DIAGNOSTICS article.
- All fuel injectors must "click." If one or more fuel injectors do NOT "click:" Check fuel injectors electrically. See FUEL INJECTOR RESISTANCE .
- If fuel injectors are Okay electrically (injector resistance). Substitute known good fuel injectors for those that fail to "click." Repeat Output DTM. See OUTPUT DIAGNOSTIC TEST MODE (DTM) in SELF-DIAGNOSTICS article.
- If substituted fuel injector(s) now "click:" Replace malfunctioning fuel injector(s). If known good fuel injector(s) still fail to "click." Check fuel injector actuation. See FUEL INJECTORS ACTUATION .
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.