3100-3400 TB swap problems!!

[19malibu97]

hey guys, so from everything ive read, this is supposed to be a direct swap. however i picked up a 3400 TB w/o sensors from an alero at the jy for my malibu. i swapped the linkage shaft and the sensors and at first my car wouldnt idle at all. i found the throttle plate set screw nut i had to extend it all the way to even get the car to idle at about 550, now the car idles fine(ish) when warm and will not idle without my foot on the gas on cold startup. i noticed the IAC passages are different on the stock tb, also there is a whistle from the intake at a certain throttle position. what do u guys think?
Thanks - Matt

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[19malibu97]

also can provide pics if needed

[3100]

Not all GM IAC valves have the same style pintle. There are several different ones, I think yours may be the wrong type for that tb

[SappySE107]

The problem is that the IAC passage is not connected to the main bore, so it can open all it wants but no air will ever get to the engine. Pull it off and grind a notch from the square to the hole in the back.

[19malibu97]

Where do i need to grind? this is the stock TB and the one i got doesnt have the passage at the top at all, i can pull the new one off tomorrow for a pic of the lack of iac passage
52mmTB.jpeg

[SappySE107]

It has a square on the one you are using and you need to notch it to look like the original. Well, not that much but you get the idea.

[19malibu97]

so i pulled the new TB off and ground out the space between the passage and the actual bore and now the car runs like it should again!! Thanks for the help fellas

[talon2swords]

I did this operation to my two cars. First one works ok when driving. But the second one makes a whistle noise in the first-second gear range. I wonder if my material-removal-job-shape is to blame, or something else.

[19malibu97]

mine whistles at a certain throttle position and rpm but it did it before and after i modified the tb, it doesnt really bother me, i think its just kinda strange