Hanging At 2,000 Rpm

Discussion in 'Fox 5.0 Mustang Tech' started by Strype, Jul 12, 2013.


  1. Strype

    Strype Cuthbert catcher Founding Member

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    B303, GT40X, 5 speed
    Hey guys this car is still hanging at 2,000 RPM for 10 seconds when out of gear then returns to idle. Every now and then it searches to 1500. Here's what's been done recently -

    TFI Module, Plugs, Cap, Rotor button, Idle Air Bypass, TPS, Coolant Temp Sensor. These are all brand new. The TPS is set at .98. I did adjust the idle screw and it sits mostly at 1,000 rpm when warm. Until it's warm it tries to idle down to 600-700. Otherwise it runs great. That B303 does NOT like to idle under 900.

    Question - Isn't there a sensor on the brake and a neutral safety switch somewhere? Could that be causing it to hang? Could it be the throttle linkage?

    I will go back through the surging idle checklist as well. I'll look at that now.
     
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  2. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    Did you reset the computer after adjusting the idle set screw? That can sometimes cause what you are seeing because the car learned how to idle..and now you've confused it.

    Perform the idle reset by unplugging the IAC and spout and adjusting the idle set screw to a low idle. This will be tough with a bcam but it should still idle. Then reset the computer, plug the IAC and spout back in and let the car relearn idle. Afer this part, do not touch the idle screw unless you reset the computer or it will cause some issues with hanging idles or high idles
     
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  3. Strype

    Strype Cuthbert catcher Founding Member

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    Okay I'll try that. Thanks
     
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  4. MFE92

    MFE92 Active Member

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    I guarantee your problem is a failing connection at the 10-pin connectors clipped to the back of the intake throat. Take them apart, clean them with MAF cleaner, then carefully tweak each individual pin so it makes a tighter fit with its mate on the other side of the connector. Reconnect and disconnect the connectors a few times so you get nice clean contacts, connect them one last time, and be done with it.
     
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