It's not normally open much at all at idle (if any really....) something to check on it though is make sure the plate that opens (I've always just called it the butterfly...) is tight, if I remeber right there are two screws that hold that plate to a little cross piece, make sure they are tight so that it isn't just flapping around in there... I'm also really curious about this missing screw....

 

Throttle should be as far closed as possible without wedging stuck. When idling,very little air goes thru the throttle. Almost all idling air goes thru that hole & thru the IACV/FITV and thru the idle bleed screw passageway.

Setting the "base" idle (IACV unplugged) at a low value (600rpm or what?) is done to allow the IACV to operatewithin it's designedrange of operation. It's not good for this valve to operate very very close to full-closed.

 

You mean my comment back up there somewhere?

At first, I just wanted to be sure that he was talking about the proper air hole that's supposed to be there. I thought (not sure?) that certain years the idle adjust screw is actually INSIDE the throttle bore. If that screw were completely missing, it would provide a large leak path to bypass the throttle. I just wanted eric to verify that the screw was actually present & accounted for.

So, Eric, is that screw missing?

 

that's my thoughts too.... I may be mistaken but I don't know of any holes that should exist in there... there should be a screw or adjustment or plug of some sort in that hole....

I'm curious about what's missing as well....

 

i got a few pics. i'm going to go clean out the body and butterfuly more just for the hell of it, plus its daytime. and i'm going to reset my IACV again now that the car is running better than ever. wont hurt. so here's what i'm working with.. i got the car and they said it was a 1990 whiich it is, with a newer 1992 engine. 2.2. with about 90k.so i dont know if that means anything. Thanks.

 

cool. i messed up with the pics. lets try this ...


<a href="http://tinypic.com" target="_blank"><img src="http://i17.tinypic.com/43pvmlj.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

<a href="http://tinypic.com" target="_blank"><img src="http://i15.tinypic.com/46ynawx.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

 

close enough. just gotta click on the second highlighted link in each html code. two pics.

 

Those two holes should be in there. They bypass air from the filter to intake when the throttle plate is closed.

When your engine is cold, the hole on the bottom should try to draw air (that is controlled by the FITV and is open). Once the engine is warm, the bottom one should not pull much air (FITV closed). You can check the FITV by starting the car and covering the bottom with your finger. You should feel a decent vacuum when the engine is cold. Once the engine is at operating temperature, you should barely feel a vacuum over that bottom hole.

Also, when the engine is warm, plug the top hole. The engine should severly sputter and shut off due to lack of air. If the engine still runs, you have an air leak somewhere (either from the FITV test from above, vac hose, or gasket problem).

 

well i took the throttle body off today and cleaned it all out darn good, put her back on, and the car ran worse than before.when i start the car, it now idel's reall high, than low than high, and so on for like 30 seconds. than stops and slows to its idle. i adjusted the throttle screw?(screw above throttle body)and the screw that the throttle hits/sits on. my buddy said to check the ECT thats connected to the thermosate housing. see the holes in the throttle is what "sounds" lke the problem is. cause when i give it throttle, i can hear the vaccume that that hole(s) creates gets real loud, holds like its sticking, than drops.. all insync with the rpm's... its like 1)tap throttle 2) vacumme hole(s)get loud like a little turbo winding up 3)noice and rpm's stay high 4)sec or so later the loud vaccume noice stops and rpm's drop... if any of that made sense. its like i can hear something sticking inside them two little holes or something.i dunno. tomorrow i will do theFITV test. thanks. Eric

 

When I took apart my throttle body, my idle was stuck at 3000 rpms. I was going crazy trying to figure out what had happened. I eventually reset my ECU, so it could relean the idle settings, and the problem was fixed.

I would pull the 7.5 amp ECU backup fuse for 30 seconds and let the car warm up to operating temp.