high idle and hanging rpms

Discussion in '96-04 - 2V Specific' started by justa2v, Apr 18, 2014.

  1. justa2v

    justa2v New Member

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    I finally got the engine in my car and I'm having high/ hanging idle issues. Its a 99 gt with 2.1 KB, 36lb injectors, 75mm tb, 90mm maf, 255lph fuel pump with KB boost a pump, manual transmission, doesn't have cats and I have the mil eliminator a for the rear o2s. I cant find a vacuum leak anywhere. New iac and pcv. I hooked the scanner up to it and here are some of the readings I wrote down:
    IAC DUTY CYCLE=48%
    MAF=9.5-9.98(GM/S)1.06-1.1volts
    IAT=143°F, 1.14volts
    ECT=192°F
    O2s11=932mv
    O2s21=964mv
    One menu said the fuel rail pressure was 37.6psi and another said it was 57psi
    What do you think?
     
  2. justa2v

    justa2v New Member

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    O and I also had a guy at the speed shop make me a run tune. He thinks its a vacuum leak
     
  3. 96blak54

    96blak54 Legend

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    Be sure the throttle butterfly is closing correctly and their are no plug type screws missing allowing air to enter.
    Definitely sounds like air freely passing the throttle.
     
  4. justa2v

    justa2v New Member

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    I've tried adjusting it a couple times. Doesnt seem to help
     
  5. justa2v

    justa2v New Member

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    Anyone?
     
  6. 96blak54

    96blak54 Legend

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    Your second post about a guy making a run tune kinda kills this thread. Go dyno tune it.
     
  7. justa2v

    justa2v New Member

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    Was wanting to break the motor in before I put boost to it