I just finished installing my ITR TB that had been bored out by RC Engineering (70mm tapered to 66mm). Here are a couple pics....




I also removed and reinstalled the intake manifold to properly match port the ITR intake manifold. Here's my dilema. It seems the throttle plate is sticking open just a little because sometimes the idle will stick at 2100rpm. If I blip the throttle it will drop down to a normal 800rpm idle. I'm a pretty experienced mechanic. I know it's not a vacuum leak because I used new gaskets all around and after I blip the throttle it idles fine. But then if I drive it for awhile it will stick at 2100rpm again for a few seconds or until I blip the throttle. If I try to repeat the problem sitting in the parking lot and slowly opening and releasing the throttle I CANNOT get it to stick. It's really weird. These are the things I have checked.....

-Throttle cable has slack in it and is not binding at all
-When idle sticks at 2100rpm the V-AFC reads 0% throttle

Anyways, as you can see I'm a bit baffled. I didn't have this problem before installing the RC TB. I called RC Engineering and they want me to send the throttle body back down to them so they can check it out. NO MORE DOWNTIME......PLEASE . I figured someone here would have an idea. My best guess is that the gray sealing stuff they use at the back of the throttle plate is binding the butterfly plate or shaft intermittently. But that's a pretty rough guess. Any ideas? Thanks.

 

Is the return on tight? Are the screws on the back of the blade tight? You could try adjusting the throttle stop a hair, or loosen the screws on the back of the blade to get it fully seated if its catching.

How old is your FITV? Did you bypass the coolant to it?

 

check your iac motor?????

 

I 2nd Teken's suggestion as it definitely sounds like there's a fault in the mechanical operation of the throttle plate.

Good luck.

 

sounds like the throttle plate isnt sealing around the t/b bore properly.......send it back.

what is your TPS voltage at closed throttle?

 

it's the same thing that happened to my JG TB...the throttle plate was replaced and it was sticking...it went away..I guess it was just really new. *shrugs*

 

Thanks for the help guys. It ended up being that the gray "sealing crap" got under the butterfly plate a bit and was binding "occasionally". It was very irritating. But it's all fixed now. I pulled it off and cleaned it up a bit. Now everything is normal.

And for anyone that wants some better throttle response, I highly recommend a bigger bore TB. SO MUCH FUN!!!. Thannks again.