Severe Engine Shudder During Acceleration
FAULT TRACING INFORMATIONConditions
^ DTCs in Motronic 1.8 absent.
^ DTCs in AW 30-43 absent.
^ Engine warm.
^ Fault permanent.
Fault Sources
^ Defective / damaged spark plug.
^ Damp in spark plug wells.
^ Resistance in Mass Air Flow (MAF) Sensor.
TESTING PROCEDURE
Check Spark Plug
^ Check if any spark plug has thin brown lines or patches on porcelain near the hexagon head.
If any spark plug defective:
- Change all spark plugs.
- Continue with: Check MAF Sensor Connector, section below.
If spark plug OK:
- Proceed to: Check MAF Sensor Connector, section below.
NOTE: It is very important that the correct spark plugs are used. Also check gaps of new plugs before fitting. Spark plug gap should be 0.7 - 0.8 mm.
Check MAF Sensor Connector
^ Clean and grease MAF sensor connector.
^ Check if symptom persist.
If vehicle continues to shudder:
- Connect breakout box.
Connect Breakout Box
^ Connect breakout box and check control points.
^ Connect ECM.
^ Check all signals to and from ECM.