1999 GMC Yukon Sudden engine racing and acceleration proble

1999 GMC YUKON
167,000 MILES • V8 • 4WD • AUTOMATIC
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NEWMEXNINA
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My daughter was driving her 1999 GMC Yukon when it started to idle very high and accelerate on its own. A diagnostic test revealed the following code: PO320 Ignition/Distributor Engine Speed Circuit Malfuntion.

Could this be causing the engine to race suddently without warning? Most of the symptoms I read about this problem seem to be related more to the engine idling very slowing and stalling.
Jun 23, 2010 at 8:39 PM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
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Try cleaning out the idle air control valve and throttle bore and test the throttle position sensor and mass airflow sensor
Jun 23, 2010 at 9:00 PM
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NEWMEXNINA
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I've printed out your possible solutions and will take them to my mechanic tomorrow.
Jun 23, 2010 at 9:22 PM
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