99 Audi A4 Stumbles on acceleration and stalls.
Aug 13, 2008 at 3:11 PM
1999 Audi A4 99 Audi A4 Stumbles on acceleration
1999 AUDI A4
ASTERPIS
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- 1 POST
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RASMATAZ
- ✓ASE Certified Mechanic
- 75,992 POSTS
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)
Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:
Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)
Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:
Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires
Aug 13, 2008 at 4:09 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.