Question about 2004 Mazda 6

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Still Rough Idle After Battery Disconnect

I recently disconnected my battery to clean the terminals. When I reconnected it, the car rough idled (as expected). However, after two weeks of driving, the problem never corrected itself. So I disconnected the battery again, and let the car idle in park for 5-10 minutes after reconnecting it, in an attempt to let the system "relearn" the proper idle. However, the problem still exists. My car continues to idle roughly while stopped at lights (and in Park) and sometimes makes a spastic drop to <500 RPM while idling at lights, before going back up to 750. It only seems to happen when the car is warm. Any ideas?

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The first thing to do is not set up the idle speed, but to set the Idle mixture screw to lean best idle setting. First, turn in the mixture screw until the engine dies or runs worse, then back out the screw (recommend turning ¼ to ½ turn at a time). The engine should pick up speed and begin to smooth out.

The battery has nothing to do with the idle speed

Posted on Apr 09, 2017


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Posted on Jan 02, 2017



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SOURCE: idles rough after engine is warm

check ALL vacuum lines for cracks/holes and replace as nesissary

Posted on Feb 25, 2010


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SOURCE: Rough idle when stopped in drive

hi barry i have the same problem did you ever fix yours ?

Posted on Jan 06, 2011

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  3. Continue applying vacuum to hose and briefly energize valve by connecting battery positive terminal to the black/yellow wire terminal and negative battery terminal to the green/black wire terminal. Valve should not hold vacuum when energized.
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