I drive a continental car. The engine speed is erratic at idle. What do you think is wrong?
Akther Hussein

It is advisable to have your car diagnosed by a workshop that is equipped with the marque's fault diagnosis equipment. Nevertheless, the following are some of the possible causes:

• Air intake/Vacuum systems - leaks
  
• Defective ignition system
  
• Defective idle air control (IAC) value
  
• Defective throttle position (TP) sensor
  
• Defective volume air flow (VAF) sensors/mass air flow (MAF) sensor
  
• Defective manifold absolute pressure sensor (MAP)
  
• Defective injector
  
• Defective engine management system - connections/wiring
  
• Defective engine control module (ECM)
  
• Defective engine coolant temperature (ECT) sensor.

Automobile Association of Singapore