Erratic idling when engine at normal temperature

2009 SUZUKI VITARA
53,000 MILES • 2.0L • 4 CYL • 2WD • AUTOMATIC
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EMCKENZIE
  • MEMBER
  • 1 POST
hi,

My Vitara is fine when I start it up and drive for 15minutes, but when the engine gets to normal temperature the idling at the stop light slowly drops to 500rpms then goes back up to seven hundred. With the a/c on it idles up to 800rpms but drops to 700 and back up to 800.

Do you know what can be the problem?
Sep 2, 2015 at 12:01 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,193 POSTS
  • ASE Certified Mechanic
Most times, a fluctuation in idle speed is caused by the idle air control valve (IAC). The IAC is responsible for maintaining a smooth idle. It could also be the result of an engine vacuum leak.
Sep 2, 2015 at 7:37 PM
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