First of all the butterfly in my throttle body was adjusted so that it would open a little more to let more air in. The reason for that was because i got a bad coolent seal on my rebuilt engine, but i thought it there wasn't enough air so i had karack open it for me. I just got it fix and now want to close down the butterfly a little bit because the idle screw on top wouldn't help it down so i was wondering how do you adjust the throttle body meaning closeing the butterfly a little bit. Thanks

 

on the front of the throttle body on top, kinda near the true idle screw is a small 8mm nut and set screw attached to the linkage on the front of the throttle body: loosen the nut and back off the screw. to set it properly, start the engine and back the screw out until the idle drops as low as it can go and then screw it in 1/4 turn and tighten the locknut. you may need to readjust the idle screw during this process to keep it from stalling out if the main idle screw is set too low.

 

thanks. Ill give it a try in my auto class tomorrow.

 

Is this the same on a T2 as on an n/a ?

 

when i play with the screw the engine has to be running right. What about the idle screw on top. does it has to be close down all the way. and then once i got it to the lowest point where i would stay idle then i adjust the idle screw on top and open it up to where the rpm suppose to be right.

 

yes it has to be running, screw the main idle screw out a bit until the idle raises as high as it will go, loosen the 8mm nut on the set screw on the front and screw out the screw until the idle drops down as low as it will go and turn the screw back in 1/4 turn and tighten the locknut back down. that's all you need to do for the secondary throttle plate adjustment. now turn the idle screw (top middle of the throttle body) in until you get the idle set.

the secondary throttle stop screw is really only there to keep the throttle plates from closing completely and making the throttle pedal feel sticky when fully closed so it uses the screw to rest on just off the fully closed position. the TII has one as well but it is underneath the throttle body as it is flipped upside down on turbo intake manifolds, there is no real reason to mess around with that screw anyways unless there is an issue causing the car to idle excessively low and it is a patch fix until the issue is fixed. the TII throttle body has a primary throttle stop screw you can use to adjust the idle on the back top of the throttle body under the intercooler. i use the secondary throttle stop screw on n/a's from time to time since they are the only accessible method for raising the idle above what the main idle screw is capable of.

 

this is for an NA. Adjusting wont help so now i have to take out the throttle body. Do i have to get new gasket for it.