I purchased a used(He said new in box) throttle body off of ebay. He managed to break a screw in the top plate,I welded a new nut to the top of the broken screw and the heat pulled it right out with out damaging the threads further, easy fix.The gasket was torn, I bought a new one. It even had deposits on the throttle plate. He said he only installed it to port the intake needless to say he ripped me off and lied, but that isn't my problem. ....
He used a pair of needle nose pliers to adjust the throttle plates open a bit. It seems the screw is o.k. but looks mangled up pretty good. What I need to know is : Do they need to be cracked open? He had them open quite far. I thought there was an opening in the TB so the car can idle. I would think by cracking them open you would be messing with the TPS. I believe the LT1 sensors are not adjustable. I closed the blades so there is an ever so slight opening. You have to hold it to the light to see anything. It does not appear to be binding or jamming, even when letting the plates slam shut.
I compared it too my stocker and the plates look to be the same, as far position of the plates. Any help would be appreciated.

This guy tried to sell me his 383 w/ lt4 heads. I can only imagine how "great" that engine was

 

Did you use the correct Torx screwdriver for the throttle stop screw?

After you install the TB, start the engine. If the idle speed is not correct, slowly back off on the stop screw until the engine reaches the programmed idle speed (A4 stock programming is 550rpm in gear, 650rpm in neutral). Best to check it with a scanner, reading the RPM from the PCM, since the stock tach routinely reads 100-200rpm high. If the idle speed is correct, check the IAC counts with a scanner. Should be in the range of 20-40 counts. Then check the TPS voltage. Any number between 0.20-0.90V will be accepted by the PCM, and used as the baseline for 0% TPP. Some people try to get the TPS back in to the normal factory range of 0.50-0.67V by slotting the TPS sensor so it can be rotated.

 

Yes, I got the throttle screw right. I knew exactly what he had done when I saw how mangled the screw was.
I haven't even fired the engine yet, still got paint to do in the engine bay, but I am going to assume my idle speed will need to be bumped a bit with my 383 and new cam(read sig).
When you say scanner, will LT1 scanmaster do?. I have yet to buy it but have seriously considered doing so. I seen a mod for installing it right in the heater duct, to the right of the instrument cluster.
I wasn't sure about the slotting of the tps sensor. Is it worth the extra time or is it something that may be required if it doesn't read the acceptable voltage?
Thanks for the help!

 

in theory, the idle screw is only a throttle stop screw

 

yes, but doesn't the tps function directly off the position of the plates?.If you crack the plates open, it would then give a "false reading" on the voltage at the tps, just to get it to idle. Like Fred said,the pcm needed an acceptable voltage. Is that right?
I guess the real question here is why he had it cracked open so far. He won't talk to me as he hung up on me when I called him after receiving the "new, in box" throttle body. He then hid behind his girlfriend after that

 

yes, all that is correct, however, as long as TPS voltage is under 1v, the PCM uses start up voltage as 0%, as for why he had it cracked open, he probably needed more air, probably needed a tune also

 

ah, I see. Can you usually run these directly "out of the box". I am just a bit nervous about firing the engine only to have it die. I have done a ton of work to the car, all engine. I think, I will fire the car to make sure it is working properly, before I install my racetronix fuel kit.