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  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

IAC/idle help

  • Thread starter Thread starter spederman
  • Start date Start date Aug 17, 2009
S

spederman

Member
Apr 13, 2005
732
0
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Aug 17, 2009
#1
  • Aug 17, 2009
  • #1
finished my bullitt intake swap and for some reason my rpm's hang @1800 until i come to a complete stop then they go down to 1000rpm. If i blip the throttle while idling, it will hang at 1800rpm again and slowly come down.

If i unplug the IAC hose, the car doesnt die or stumbe, the rpm's actually go up and idle at 1200rpm. IF i unplug the electrical connector to the IAC valve, the car idles PERFECT @700rpm. The rpms dont hang at all, if i blip the throttle they drop instantly and the car stays running. Shouldnt it die without it? What could be wrong?
 

trombonedemon

Well-Known Member
Jun 25, 2009
1,962
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U.S.A, U.S.A., U.S.A.!
Aug 18, 2009
#2
  • Aug 18, 2009
  • #2
Sounds like you have manifold leak to me, I'll tell you why, I put an intake spacer above the manifold and put the gasket on the wrong side, and it was pulling way too much air, and it took a while to settle to an idle.
 

GDawg

Founding Member
Mar 22, 2002
1,469
19
68
Nevada
Aug 20, 2009
#3
  • Aug 20, 2009
  • #3
vacuum leak...
 
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