1999 Ford Explorer Doesn't Maintain Idle

87,000 MILES • 6 CYL • 4WD • AUTOMATIC
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BSCHLANGER
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  • 2 POSTS
The car doesn't want to idle after sitting for longer periods of time (overnight). Need to keep foot on accelerator to let it warm up, once its warmed up it'll maintain an idle but relatively high, otherwise it'll stall.
Codes have been read;
P0171 - System 2 lean, Bank 1
P0174 - System 2 lean, Bank 2
P0300 - Cylinder Misfire
There is a noticeable smell of unburned gasoline when the car starts up.

I checked the IAC seemed fine and was thinking of changing out the spark plugs next. Any ideas would be greatly appreciated.
Feb 1, 2010 at 6:05 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,246 POSTS
Check the EGR and for vacuum leaks. If you are getting a lean mixture on both banks, chances are you have a leak.

Let me know what you find.

Joe
Feb 5, 2010 at 5:35 AM
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BSCHLANGER
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Finally got time to get everything checked out and it turns out it was a vacuum leak on the manifold.

Thanks for all your help.
May 18, 2010 at 4:12 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,246 POSTS
That is what I thought. It is (in my book) the number one cause of a lean mixture.

Let us know if you have other questions in the future.

Joe
May 18, 2010 at 4:16 AM
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