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Q: Rough Idle Problem

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The check engine light is not on! Car idles rough at a stop at times it will shut off. However it does start back up. When I accelerate the car makes a loud rumbling and shaking noice. Car was recently tuned up due to the same problem. Fixed it for about a month. What could be wrong?

My car has 90000 miles.
My car has an automatic transmission.

A rough idle may be caused by many different things such as low fuel pressure, low voltage to the fuel injectors, dirty fuel injectors, a vacuum leak, a faulty Oxygen sensor or a dirty or failing idle air control valve. Any of these possibilities relate to fuel delivery issues that will disrupt the normally balanced air/fuel mixture that would otherwise allow the motor to run smoothly. I would recommend having an expert from YourMechanic cometo your location to diagnose your rough idle problem.

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