IAC

The bolt you are talking about, it sounds like you mean the idle stop screw. The screw you turn to adjust your idle speed. You probably have it turned back way too far. First, unplug your IAC sensor after the engine has warmed up, then adjust the screw till your idle speed is around 750 RPM. I have an ear for that, but you should adjust a little ... then look at your Tach. When the idle speed is aroun 725 - 775 RPM, stop then plug the IAC back in. Wait a minute after plugging it back in then blip the throttle quickly. When I say "Blip" I mean push it forward quickly and then let go. Then slowly press the throttle till its near around 2500 RPM... then let off. Your idle speed should return to normal (around 750 RPM). If it does not, and idles too high still, then the IAC is faulty. Cleaning the IAC does not always fix a sticking IAC plunger. Sometimes the plunger seal is just too eroded or worn that it cannot keep a tight air seal. In some cases, replacement is your only option.

If you engine is idling high and you unplug the IAC, how far do the RPM's drop? I mean exactly? If the engine has been running for awhile and the idle RPM's are still high (around 2000 RPM ), and you unplug the IAC and it does not drop below 1000 RPM, there is a vacuum leak someplace. But first, make sure you adjust the idle speed correctly. Follow the method I gave you and go from there. If... the plunger seal inside the IAC is so badly worn..or stuck..sometimes unpluging it don't drop the idle, to verify if the IAC may still be at fault, unbolt the IAC from the throttle body. Plug the two holes on the top of the throttle body with something. Make sure whatever you use to plug the back side hole is large enough because it CAN get sucked in....and you DONT want that. Basically you want to completely disconnect the IAC from the engine and plug those holes perfectly to simulate a mounted IAC that doesn't have a bad seal. Make sure the holes stay plugged 100% all the time. The slightest leak will screw up your idle speed. You want to see if the idle speed will return to normal speeds with the holes plugged and the screw set properly.

Let me know if you need more help with this.

Not a problem. But can you make a new thread in the technical forum. Thats where your problems and anything technical related to fixing your stang goes.... here its just Stang chit chat. And you dont get credit for your posts in the talk section This just makes it easier so the mods dont have to keep moving threads... aint that right Gearbanger .

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