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Sun, Sep 06, 2009
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My car engine has an erratic idling speed of 500-1,000rpm. After cleaning the air flow sensor and the throttle body, the problem still exists. What other suspects are there?

QN: My car engine has an erratic idling speed of 500-1,000rpm. After cleaning the air flow sensor and the throttle body, the problem still exists. What other suspects are there?

Sent in by Alvin

ANS: The following are some possible problems for erratic idling in Japanese cars:

1. Air intake/vacuum systems are leaking
2. Fuel pressure/fuel pressure regulator
3. Oxygen sensor
4. Idle air control (IAC) valve
5. Manifold absolute pressure (MAP) sensor
6. Engine management system - connections/wiring/relays

It would also be advised to send your car to a workshop that is familiar with your car make for checking and servicing.

Automobile Association of Singapore

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STORY INDEX
 
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>> RELATED STORY
My car engine has an erratic idling speed of 500-1,000rpm. After cleaning the air flow sensor and the throttle body, the problem still exists. What other suspects are there?
I am driving a 2006 Corolla and recently the valve movement sound (I think) seem to be louder (only when moving).
Do I need to shift to "P" when I'm at a red traffic light? I drive an automatic car.
When turning the car, croaking sound is heard occasionally. What is the problem?
Why does my car jerk, have a hard time accelerating and emit a pinging sound?
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