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Q: I have a question about rough idle

asked by on December 14, 2016

I have been having some starting issues and rough idle for about two months. I've noticed when I start the vehicle I have to crank for at least 2.5 sec. It used to start right up. Now when it's idling in drive at a stop light the truck is vibrating. But the rpms are fine. I've tried replacing the battery with a new one. Same issue. Maybe my fuel injectors need cleaning? I've had a tune up just this year. The vibration isn't big but noticeable. The engine and transmission are still going strong. Maybe the throttle body is dirty?

My car has 264000 miles.
My car has an automatic transmission.

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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.

Mercury
engine idle
1999
V8-5.0L
Mountaineer
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